#0f172a

#0f172a is rgb(15, 23, 42), or hsl(222, 47%, 11%). The nearest reference Tailwind v4 token is slate-900 (#0f172b), not an exact match.

Conversions

WCAG contrast

Background	Ratio	AA text	AA large	AAA text
white	17.85:1	pass	pass	pass
black	1.18:1	fail	fail	fail
slate-900	1.00:1	fail	fail	fail
gray-100	16.22:1	pass	pass	pass

Ratios use WCAG relative luminance for opaque sRGB colors. Normal text requires 4.5:1, or 7:1 at AAA. Large text requires 3:1: at least 24 CSS pixels, or about 18.67 CSS pixels when bold. Pass/fail uses the unrounded ratio. Contrast alone is not a full accessibility assessment.

Colors paired with #0f172a in real UI palettes

These colors appear alongside #0f172a in StyleKit's curated palettes. Co-occurrence is not a promise of text readability; each pair includes its measured contrast.

#f59e0b
Used together in Dark Mode, Z-Pattern Layout.
8.31:1
AA normal text
#06b6d4
Used together in Z-Pattern Layout.
7.35:1
AA normal text
#22c55e
Used together in Dark Mode.
7.83:1
AA normal text
#3b82f6
Used together in Dark Mode.
4.85:1
AA normal text
#6366f1
Used together in Z-Pattern Layout.
4.00:1
Not for normal text
#ec4899
Used together in Z-Pattern Layout.
5.06:1
AA normal text

A readable starting point

white text on #0f172a: 17.85:1 contrast.

Design styles using this color

Tints and shades

#bcc9e7

#7993cf

#3f60b0

#273c6d

#0c1222

#090e19

#060911

#030508

Lightness ladder in HSL space, from the lightest tint to the darkest shade of #0f172a.

Similar colors in the library

#111827 #141821 #1a1a2e #1a1225 #1a1c2c #0f0e2e #0f1419 #1a1c22

Nearest swatches by perceptual OKLab distance across all curated style palettes.

AI prompt snippet

Use #0f172a as the secondary color, following the Dark Mode style: rgb(15, 23, 42), nearest Tailwind token slate-900. Keep text contrast at least 4.5:1 (this color scores 17.85:1 on white, 1.18:1 on black).

Paste this into ChatGPT, Claude, Cursor, or v0 to use #0f172a with correct contrast constraints. Browse all palette colors.

Questions about #0f172a

What color is #0f172a?

#0f172a is rgb(15, 23, 42), or hsl(222, 47%, 11%). The nearest reference Tailwind v4 token is slate-900 (#0f172b), not an exact match.

What text color should I use on #0f172a?

White (#ffffff) has the higher black-or-white contrast against #0f172a: 17.85:1. This calculation assumes opaque, flat sRGB colors. Normal text requires 4.5:1 and large text 3:1 under WCAG 2.2 SC 1.4.3; it is not a complete accessibility assessment.

How can I use exactly #0f172a in Tailwind CSS?

Use bg-[#0f172a], text-[#0f172a], or a CSS custom property instead of substituting a nearby named token. The reference palette is Tailwind CSS 4.1.18, converted from OKLCH to sRGB hex; newer Tailwind versions and custom themes can differ.

Sources and calculation limits

Reference palette: Tailwind CSS 4.1.18, converted from OKLCH to sRGB hex. Named tokens are versioned approximations; use the exact hex utilities when matching an existing design. Palette pairings come from the linked StyleKit definitions, not external popularity or preference data.