Background
Background utilities paint an element with a theme colour, a subtle tint, the body surface or a gradient. Combine bg-{colour} with bg-opacity-* or the --ui-bg-opacity variable to fade it, and prefer the text-bg-* helpers or -emphasis text colours so contrast stays readable in light and dark mode.
1Theme colour backgrounds
bg-primary to bg-dark fill an element with a theme colour. Pair them with a readable text colour - text-bg-primary picks the one that reads on your brand colour.
<div class="row g-2 small">
<div class="col-6 col-md-3">
<div class="text-bg-primary rounded-2 p-3">
bg-primary
</div>
</div>
<div class="col-6 col-md-3">
<div class="text-bg-secondary rounded-2 p-3">
bg-secondary
</div>
</div>
<div class="col-6 col-md-3">
<div class="bg-success text-white rounded-2 p-3">
bg-success
</div>
</div>
<div class="col-6 col-md-3">
<div class="bg-danger text-white rounded-2 p-3">
bg-danger
</div>
</div>
<div class="col-6 col-md-3">
<div class="bg-warning text-dark rounded-2 p-3">
bg-warning
</div>
</div>
<div class="col-6 col-md-3">
<div class="bg-info text-dark rounded-2 p-3">
bg-info
</div>
</div>
<div class="col-6 col-md-3">
<div class="bg-light text-dark rounded-2 p-3 border">
bg-light
</div>
</div>
<div class="col-6 col-md-3">
<div class="text-bg-dark rounded-2 p-3">
bg-dark
</div>
</div>
</div>2Subtle backgrounds
The -subtle variants are soft tints that work in light and dark mode; use the matching -emphasis text colour.
<div class="d-grid gap-2">
<div class="bg-primary-subtle text-primary-emphasis rounded-3 px-3 py-2">
bg-primary-subtle
</div>
<div class="bg-success-subtle text-success-emphasis rounded-3 px-3 py-2">
bg-success-subtle
</div>
<div class="bg-warning-subtle text-warning-emphasis rounded-3 px-3 py-2">
bg-warning-subtle
</div>
<div class="bg-danger-subtle text-danger-emphasis rounded-3 px-3 py-2">
bg-danger-subtle
</div>
<div class="bg-info-subtle text-info-emphasis rounded-3 px-3 py-2">
bg-info-subtle
</div>
</div>3Body backgrounds
bg-body, bg-body-secondary and bg-body-tertiary follow the page surface and adapt to colour mode.
bg-body - the page itselfbg-body-secondary - side panelsbg-body-tertiary - wells and inputs<div class="border rounded-4 overflow-hidden">
<div class="bg-body p-3 border-bottom">
<code>bg-body</code> - the page itself
</div>
<div class="bg-body-secondary p-3 border-bottom">
<code>bg-body-secondary</code> - side panels
</div>
<div class="bg-body-tertiary p-3">
<code>bg-body-tertiary</code> - wells and inputs
</div>
</div>4Text and background together
text-bg-{colour} sets the background and a contrasting text colour in one class.
<div class="d-flex flex-wrap gap-2">
<span class="text-bg-primary rounded-pill px-3 py-1">text-bg-primary</span> <span class="text-bg-warning rounded-pill px-3 py-1">text-bg-warning</span> <span class="text-bg-info rounded-pill px-3 py-1">text-bg-info</span> <span class="text-bg-light rounded-pill px-3 py-1 border">text-bg-light</span> <span class="text-bg-dark rounded-pill px-3 py-1">text-bg-dark</span>
</div>5Background opacity steps
bg-opacity-10, -25, -50, -75 and -100 fade a theme background in fixed steps. White text needs the full colour; the labels sit under the lighter steps.
<div class="d-flex flex-wrap gap-3 small text-center">
<div>
<div class="bg-success bg-opacity-100 rounded-3 mb-1" style="width:4rem;height:3rem">
</div>
100
</div>
<div>
<div class="bg-success bg-opacity-75 rounded-3 mb-1" style="width:4rem;height:3rem">
</div>
75
</div>
<div>
<div class="bg-success bg-opacity-50 rounded-3 mb-1" style="width:4rem;height:3rem">
</div>
50
</div>
<div>
<div class="bg-success bg-opacity-25 rounded-3 mb-1" style="width:4rem;height:3rem">
</div>
25
</div>
<div>
<div class="bg-success bg-opacity-10 rounded-3 mb-1" style="width:4rem;height:3rem">
</div>
10
</div>
</div>6Gradient overlay
bg-gradient adds a soft white-to-transparent gradient on top of any bg-{colour}.
<div class="row g-2">
<div class="col-sm-6">
<div class="bg-primary bg-gradient text-white rounded-4 p-4">
<div class="fw-semibold">
bg-primary bg-gradient
</div>
<div class="small text-white-50">
Online results
</div>
</div>
</div>
<div class="col-sm-6">
<div class="bg-dark bg-gradient text-white rounded-4 p-4">
<div class="fw-semibold">
bg-dark bg-gradient
</div>
<div class="small text-white-50">
Reminders
</div>
</div>
</div>
</div>7Transparent background
bg-transparent removes a fill, useful when a component's default background must disappear.
<div class="bg-body-tertiary rounded-3 p-3 d-flex flex-wrap gap-2">
<div class="bg-white text-dark border rounded-2 px-3 py-2 small">
bg-white
</div>
<div class="bg-transparent border rounded-2 px-3 py-2 small">
bg-transparent
</div>
<button type="button" class="btn btn-light bg-transparent border-0 text-body"><i class="bi bi-three-dots" aria-hidden="true"></i> Ghost button</button>
</div>8Black and white
bg-black and bg-white are fixed colours that do not change with colour mode, unlike bg-body.
<div class="d-flex rounded-3 overflow-hidden border">
<div class="bg-black text-white flex-fill p-3 text-center small">
bg-black
</div>
<div class="bg-white text-black flex-fill p-3 text-center small">
bg-white
</div>
</div>9Highlighted table row
Background utilities on a table cell or row mark a selection without extra CSS.
| Order | Customer | Total |
|---|---|---|
| #ORD-2307 | Amara Kowalski | $123.39 |
| #TX-6139 | Samir Ashford | $147.79 |
| #ORD-6055 | Mason Moreau | $184.24 |
<div class="table-responsive">
<table class="table table-sm mb-0 align-middle">
<thead>
<tr>
<th scope="col">Order</th>
<th scope="col">Customer</th>
<th scope="col" class="text-end">Total</th>
</tr>
</thead>
<tbody>
<tr>
<td>#ORD-2307</td>
<td>Amara Kowalski</td>
<td class="text-end">$123.39</td>
</tr>
<tr>
<td class="bg-primary-subtle">#TX-6139</td>
<td class="bg-primary-subtle">Samir Ashford</td>
<td class="bg-primary-subtle text-end fw-semibold">$147.79</td>
</tr>
<tr>
<td>#ORD-6055</td>
<td>Mason Moreau</td>
<td class="text-end">$184.24</td>
</tr>
</tbody>
</table>
</div>10Feature icons on tinted circles
A subtle background with rounded-circle and fixed size gives each icon a soft colour badge.
<div class="row g-3">
<div class="col-sm-4 d-flex gap-2 align-items-center">
<span class="bg-primary-subtle text-primary rounded-circle d-inline-flex align-items-center justify-content-center fs-5" style="width:44px;height:44px"><i class="bi bi-lightning-charge-fill" aria-hidden="true"></i></span><span class="small fw-medium">Certified specialists</span>
</div>
<div class="col-sm-4 d-flex gap-2 align-items-center">
<span class="bg-success-subtle text-success rounded-circle d-inline-flex align-items-center justify-content-center fs-5" style="width:44px;height:44px"><i class="bi bi-shield-check" aria-hidden="true"></i></span><span class="small fw-medium">Reminders</span>
</div>
<div class="col-sm-4 d-flex gap-2 align-items-center">
<span class="bg-danger-subtle text-danger rounded-circle d-inline-flex align-items-center justify-content-center fs-5" style="width:44px;height:44px"><i class="bi bi-heart-fill" aria-hidden="true"></i></span><span class="small fw-medium">Online results</span>
</div>
</div>11Section bands
Alternating bg-body and bg-body-tertiary bands separate page sections.
Care for the whole family
We work with most insurance providers and explain any costs upfront.
See a specialist this week
We keep things simple, so you can focus on what matters to you.
Modern healthcare close to home
Thousands of patients already trust us, and we work hard to keep it that way.
<div class="border rounded-4 overflow-hidden">
<section class="bg-body p-4">
<h3 class="h6 mb-1">Care for the whole family</h3>
<p class="small mb-0 text-body-secondary">We work with most insurance providers and explain any costs upfront.</p>
</section>
<section class="bg-body-tertiary p-4">
<h3 class="h6 mb-1">See a specialist this week</h3>
<p class="small mb-0 text-body-secondary">We keep things simple, so you can focus on what matters to you.</p>
</section>
<section class="bg-body p-4">
<h3 class="h6 mb-1">Modern healthcare close to home</h3>
<p class="small mb-0 text-body-secondary">Thousands of patients already trust us, and we work hard to keep it that way.</p>
</section>
</div>12Dark footer strip
bg-dark with text-white-50 and link-light builds a compact footer.
<footer class="bg-dark text-white-50 rounded-3 p-3 d-flex flex-column flex-sm-row justify-content-between gap-2 small">
<span>© Brioo</span> <span class="d-flex gap-3"><a href="#" class="link-light">Privacy</a><a href="#" class="link-light">Terms</a><a href="#" class="link-light">Contact</a></span>
</footer>13Alert-like message
A message strip built from bg-danger-subtle, a matching border and emphasis text.
<div class="bg-danger-subtle border border-danger-subtle text-danger-emphasis rounded-3 p-3 d-flex gap-2" role="alert">
<span class="fs-5"><i class="bi bi-exclamation-octagon-fill" aria-hidden="true"></i></span>
<div>
<strong>Payment failed.</strong> <span class="small">Video consultations let you speak with a doctor from the comfort of home.</span>
</div>
</div>14Background on hoverable list
List items with bg-body-tertiary for the active one; other rows stay on bg-body.
- Inbox
- Starred
- Sent
- Archive
<ul class="list-unstyled border rounded-3 mb-0 overflow-hidden" style="max-width:20rem">
<li class="px-3 py-2 bg-body border-bottom"><i class="bi bi-inbox" aria-hidden="true"></i> Inbox</li>
<li class="px-3 py-2 bg-body-tertiary border-bottom fw-semibold"><i class="bi bi-star-fill" aria-hidden="true"></i> Starred</li>
<li class="px-3 py-2 bg-body border-bottom"><i class="bi bi-send" aria-hidden="true"></i> Sent</li>
<li class="px-3 py-2 bg-body"><i class="bi bi-archive" aria-hidden="true"></i> Archive</li>
</ul>15Progress made from backgrounds
A bg-body-secondary track and a bg-success fill with a width utility form a simple meter.
<div class="d-grid gap-3">
<div>
<div class="d-flex justify-content-between small mb-1">
<span>Storage</span><span>75 of 100 GB</span>
</div>
<div class="bg-body-secondary rounded-pill" style="height:8px">
<div class="bg-success rounded-pill h-100 w-75">
</div>
</div>
</div>
<div>
<div class="d-flex justify-content-between small mb-1">
<span>Seats</span><span>5 of 20</span>
</div>
<div class="bg-body-secondary rounded-pill" style="height:8px">
<div class="bg-warning rounded-pill h-100 w-25">
</div>
</div>
</div>
</div>16Pricing highlight
The recommended plan gets text-bg-primary (the brand colour with the text colour that reads on it); the others stay on bg-body-tertiary.
<div class="row g-2 text-center">
<div class="col-4">
<div class="bg-body-tertiary rounded-3 p-3">
<div class="small">
Basic
</div>
<div class="fs-5 fw-bold">
$8.50
</div>
</div>
</div>
<div class="col-4">
<div class="text-bg-primary rounded-3 p-3">
<div class="small">
Pro
</div>
<div class="fs-5 fw-bold">
$28.12
</div>
</div>
</div>
<div class="col-4">
<div class="bg-body-tertiary rounded-3 p-3">
<div class="small">
Team
</div>
<div class="fs-5 fw-bold">
$80.45
</div>
</div>
</div>
</div>17Colour swatches
Square swatches with bg-{colour} and a caption below, as used in a style guide.
<div class="d-flex flex-wrap gap-3">
<figure class="mb-0 text-center">
<div class="bg-primary rounded-3" style="width:56px;height:56px">
</div>
<figcaption class="small mt-1">Primary</figcaption>
</figure>
<figure class="mb-0 text-center">
<div class="bg-secondary rounded-3" style="width:56px;height:56px">
</div>
<figcaption class="small mt-1">Secondary</figcaption>
</figure>
<figure class="mb-0 text-center">
<div class="bg-success rounded-3" style="width:56px;height:56px">
</div>
<figcaption class="small mt-1">Success</figcaption>
</figure>
<figure class="mb-0 text-center">
<div class="bg-warning rounded-3" style="width:56px;height:56px">
</div>
<figcaption class="small mt-1">Warning</figcaption>
</figure>
<figure class="mb-0 text-center">
<div class="bg-body-secondary border rounded-3" style="width:56px;height:56px">
</div>
<figcaption class="small mt-1">Surface</figcaption>
</figure>
</div>18Card header and footer tints
bg-body-tertiary on the header and footer of a card, bg-body in the middle.
<div class="border rounded-3 overflow-hidden" style="max-width:24rem">
<div class="bg-body-tertiary px-3 py-2 border-bottom fw-semibold small">
Simple habits for a healthier back
</div>
<div class="bg-body p-3 small">
Every detail is handled by people who care about getting it right.
</div>
<div class="bg-body-tertiary px-3 py-2 border-top small text-body-secondary">
Updated just now
</div>
</div>19Image scrim with bg-black
A bg-black layer at reduced --ui-bg-opacity makes white text readable over a photo.
<div class="position-relative rounded-4 overflow-hidden" style="max-width:28rem">
<img src="https://images.unsplash.com/photo-1758691462878-6edc3d3da1be?auto=format&fit=crop&w=1600&h=700&q=70" alt="Get answers, get better" class="w-100 d-block">
<div class="position-absolute top-0 start-0 w-100 h-100 bg-black d-flex align-items-center justify-content-center" style="--ui-bg-opacity:.45">
<span class="text-white fs-5 fw-semibold text-center px-3">Healthcare that fits your life</span>
</div>
</div>20Chat bubbles
Incoming messages on bg-body-tertiary, outgoing on bg-primary, each with a rounded corner set.
<div class="d-flex flex-column gap-2" style="max-width:24rem">
<div class="align-self-start bg-body-tertiary rounded-4 rounded-bottom-0 px-3 py-2 small">
Friendly reminders make sure you never miss a check-up or a dose.
</div>
<div class="align-self-end text-bg-primary rounded-4 rounded-bottom-0 px-3 py-2 small">
We measure success by how many patients come back and tell their friends.
</div>
<div class="align-self-start bg-body-tertiary rounded-4 rounded-bottom-0 px-3 py-2 small">
Family plans cover check-ups and vaccinations for everyone under one roof.
</div>
</div>