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-md p-4">
bg-primary
</div>
</div>
<div class="col-6 col-md-3">
<div class="text-bg-secondary rounded-md p-4">
bg-secondary
</div>
</div>
<div class="col-6 col-md-3">
<div class="bg-success text-white rounded-md p-4">
bg-success
</div>
</div>
<div class="col-6 col-md-3">
<div class="bg-danger text-white rounded-md p-4">
bg-danger
</div>
</div>
<div class="col-6 col-md-3">
<div class="bg-warning text-dark rounded-md p-4">
bg-warning
</div>
</div>
<div class="col-6 col-md-3">
<div class="bg-info text-dark rounded-md p-4">
bg-info
</div>
</div>
<div class="col-6 col-md-3">
<div class="bg-light text-dark rounded-md p-4 border">
bg-light
</div>
</div>
<div class="col-6 col-md-3">
<div class="text-bg-dark rounded-md p-4">
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="grid gap-2">
<div class="bg-primary-subtle text-primary-emphasis rounded-lg px-4 py-2">
bg-primary-subtle
</div>
<div class="bg-success-subtle text-success-emphasis rounded-lg px-4 py-2">
bg-success-subtle
</div>
<div class="bg-warning-subtle text-warning-emphasis rounded-lg px-4 py-2">
bg-warning-subtle
</div>
<div class="bg-danger-subtle text-danger-emphasis rounded-lg px-4 py-2">
bg-danger-subtle
</div>
<div class="bg-info-subtle text-info-emphasis rounded-lg px-4 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-xl overflow-hidden">
<div class="bg-page p-4 border-b">
<code>bg-body</code> - the page itself
</div>
<div class="bg-surface-2 p-4 border-b">
<code>bg-body-secondary</code> - side panels
</div>
<div class="bg-surface-3 p-4">
<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="flex flex-wrap gap-2">
<span class="text-bg-primary rounded-full px-4 py-1">text-bg-primary</span> <span class="text-bg-warning rounded-full px-4 py-1">text-bg-warning</span> <span class="text-bg-info rounded-full px-4 py-1">text-bg-info</span> <span class="text-bg-light rounded-full px-4 py-1 border">text-bg-light</span> <span class="text-bg-dark rounded-full px-4 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="flex flex-wrap gap-4 small text-center">
<div>
<div class="bg-success/100 rounded-lg mb-1" style="width:4rem;height:3rem">
</div>
100
</div>
<div>
<div class="bg-success/75 rounded-lg mb-1" style="width:4rem;height:3rem">
</div>
75
</div>
<div>
<div class="bg-success/50 rounded-lg mb-1" style="width:4rem;height:3rem">
</div>
50
</div>
<div>
<div class="bg-success/25 rounded-lg mb-1" style="width:4rem;height:3rem">
</div>
25
</div>
<div>
<div class="bg-success/10 rounded-lg 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-xl p-6">
<div class="font-semibold">
bg-primary bg-gradient
</div>
<div class="small text-white/50">
Sustainable materials
</div>
</div>
</div>
<div class="col-sm-6">
<div class="bg-dark bg-gradient text-white rounded-xl p-6">
<div class="font-semibold">
bg-dark bg-gradient
</div>
<div class="small text-white/50">
Sustainable materials
</div>
</div>
</div>
</div>7Transparent background
bg-transparent removes a fill, useful when a component's default background must disappear.
<div class="bg-surface-3 rounded-lg p-4 flex flex-wrap gap-2">
<div class="bg-white text-dark border rounded-md px-4 py-2 small">
bg-white
</div>
<div class="bg-transparent border rounded-md px-4 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="flex rounded-lg overflow-hidden border">
<div class="bg-black text-white flex-auto p-4 text-center small">
bg-black
</div>
<div class="bg-white text-black flex-auto p-4 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 |
|---|---|---|
| #PO-4915 | Ruby Ortega | $68.84 |
| #INV-5369 | Aria Novak | $51.70 |
| #ORD-8595 | Nadia Nguyen | $336.68 |
<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>#PO-4915</td>
<td>Ruby Ortega</td>
<td class="text-end">$68.84</td>
</tr>
<tr>
<td class="bg-primary-subtle">#INV-5369</td>
<td class="bg-primary-subtle">Aria Novak</td>
<td class="bg-primary-subtle text-end font-semibold">$51.70</td>
</tr>
<tr>
<td>#ORD-8595</td>
<td>Nadia Nguyen</td>
<td class="text-end">$336.68</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 flex gap-2 items-center">
<span class="bg-primary-subtle text-primary-ink rounded-full inline-flex items-center justify-center text-lg" style="width:44px;height:44px"><i class="bi bi-lightning-charge-fill" aria-hidden="true"></i></span><span class="small font-medium">Carbon-neutral delivery</span>
</div>
<div class="col-sm-4 flex gap-2 items-center">
<span class="bg-success-subtle text-success-emphasis rounded-full inline-flex items-center justify-center text-lg" style="width:44px;height:44px"><i class="bi bi-shield-check" aria-hidden="true"></i></span><span class="small font-medium">Sustainable materials</span>
</div>
<div class="col-sm-4 flex gap-2 items-center">
<span class="bg-danger-subtle text-danger-emphasis rounded-full inline-flex items-center justify-center text-lg" style="width:44px;height:44px"><i class="bi bi-heart-fill" aria-hidden="true"></i></span><span class="small font-medium">Sustainable materials</span>
</div>
</div>11Section bands
Alternating bg-body and bg-body-tertiary bands separate page sections.
Small batches, big on quality
Each product is checked by hand before it goes into the box.
Pieces you will reach for every day
Every detail is handled by people who care about getting it right.
Good things, made to be used
Pay securely with card, wallet or in three interest-free instalments.
<div class="border rounded-xl overflow-hidden">
<section class="bg-page p-6">
<h3 class="h6 mb-1">Small batches, big on quality</h3>
<p class="small mb-0 text-muted">Each product is checked by hand before it goes into the box.</p>
</section>
<section class="bg-surface-3 p-6">
<h3 class="h6 mb-1">Pieces you will reach for every day</h3>
<p class="small mb-0 text-muted">Every detail is handled by people who care about getting it right.</p>
</section>
<section class="bg-page p-6">
<h3 class="h6 mb-1">Good things, made to be used</h3>
<p class="small mb-0 text-muted">Pay securely with card, wallet or in three interest-free instalments.</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-lg p-4 flex flex-col sm:flex-row justify-between gap-2 small">
<span>© Mira Point</span> <span class="flex gap-4"><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/30 text-danger-emphasis rounded-lg p-4 flex gap-2" role="alert">
<span class="text-lg"><i class="bi bi-exclamation-octagon-fill" aria-hidden="true"></i></span>
<div>
<strong>Payment failed.</strong> <span class="small">Start in minutes and get help from a real person whenever you need it.</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-lg mb-0 overflow-hidden" style="max-width:20rem">
<li class="px-4 py-2 bg-page border-b"><i class="bi bi-inbox-fill" aria-hidden="true"></i> Inbox</li>
<li class="px-4 py-2 bg-surface-3 border-b font-semibold"><i class="bi bi-star-fill" aria-hidden="true"></i> Starred</li>
<li class="px-4 py-2 bg-page border-b"><i class="bi bi-send-fill" aria-hidden="true"></i> Sent</li>
<li class="px-4 py-2 bg-page"><i class="bi bi-archive-fill" 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="grid gap-4">
<div>
<div class="flex justify-between small mb-1">
<span>Storage</span><span>75 of 100 GB</span>
</div>
<div class="bg-surface-2 rounded-full" style="height:8px">
<div class="bg-success rounded-full h-full w-3/4">
</div>
</div>
</div>
<div>
<div class="flex justify-between small mb-1">
<span>Seats</span><span>5 of 20</span>
</div>
<div class="bg-surface-2 rounded-full" style="height:8px">
<div class="bg-warning rounded-full h-full w-1/4">
</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-surface-3 rounded-lg p-4">
<div class="small">
Basic
</div>
<div class="text-lg font-bold">
$6.87
</div>
</div>
</div>
<div class="col-4">
<div class="text-bg-primary rounded-lg p-4">
<div class="small">
Pro
</div>
<div class="text-lg font-bold">
$24.47
</div>
</div>
</div>
<div class="col-4">
<div class="bg-surface-3 rounded-lg p-4">
<div class="small">
Team
</div>
<div class="text-lg font-bold">
$91.83
</div>
</div>
</div>
</div>17Colour swatches
Square swatches with bg-{colour} and a caption below, as used in a style guide.
<div class="flex flex-wrap gap-4">
<figure class="mb-0 text-center">
<div class="bg-primary rounded-lg" 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-lg" 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-lg" 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-lg" style="width:56px;height:56px">
</div>
<figcaption class="small mt-1">Warning</figcaption>
</figure>
<figure class="mb-0 text-center">
<div class="bg-surface-2 border rounded-lg" 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-lg overflow-hidden" style="max-width:24rem">
<div class="bg-surface-3 px-4 py-2 border-b font-semibold small">
Our favourite tips for busy weeks
</div>
<div class="bg-page p-4 small">
Order before 2 pm and most items leave our warehouse the same day.
</div>
<div class="bg-surface-3 px-4 py-2 border-t small text-muted">
Updated 16 hours ago
</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="relative rounded-xl overflow-hidden" style="max-width:28rem">
<img src="https://images.unsplash.com/photo-1601647998829-ee316a565aea?auto=format&fit=crop&w=1600&h=700&q=70" alt="Quality goods delivered to your door" class="w-full block">
<div class="absolute top-0 start-0 w-full h-full bg-black flex items-center justify-center" style="--ui-bg-opacity:.45">
<span class="text-white text-lg font-semibold text-center px-4">Designed to last, priced to love</span>
</div>
</div>20Chat bubbles
Incoming messages on bg-body-tertiary, outgoing on bg-primary, each with a rounded corner set.
<div class="flex flex-col gap-2" style="max-width:24rem">
<div class="self-start bg-surface-3 rounded-xl rounded-b-none px-4 py-2 small">
Gift wrapping and a handwritten note are free on every order.
</div>
<div class="self-end text-bg-primary rounded-xl rounded-b-none px-4 py-2 small">
Free shipping on orders over $50 and easy returns within 30 days.
</div>
<div class="self-start bg-surface-3 rounded-xl rounded-b-none px-4 py-2 small">
Our packaging is plastic-free and every delivery is carbon-neutral.
</div>
</div>