#15173A
Closest named color: Rich Black (#0D1B2A). oklch(22.5% 0.066 277.2), rgb(21, 23, 58).
Aa
White text reads best on this color (17.27:1).
About this color
#15173A is a very dark, muted blue. In OKLCH its lightness is 23%, its chroma 0.066 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.039 away. White text reads best on it, at 17.27:1.
| Hue family | Blues |
| Lightness | very dark (23%) |
| Chroma | muted (0.066) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.21:1 |
| White text | 17.27:1 |
Values
| HEX | #15173A |
| RGB | rgb(21, 23, 58) |
| HSL | hsl(237, 47%, 15%) |
| OKLCH | oklch(22.5% 0.066 277.2) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #15173A | 17.27:1 | AAA | Lc -106.4 | Preferred for body text |
| Black text on #15173A | 1.21:1 | Fails | Lc 0.0 | Not readable |
| #15173A text on white | 17.27:1 | AAA | Lc 104.0 | Preferred for body text |
| #15173A text on black | 1.21:1 | Fails | Lc 0.0 | Not readable |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 950.
-
Step 50
50
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E6E9F9
oklch(93.6% 0.022 277.5)
-
Step 200
200
#D1D7F7
oklch(88.5% 0.044 277.1)
-
Step 300
300
#B3BDF4
oklch(81% 0.079 276.5)
-
Step 400
400
#8D98EE
oklch(70.6% 0.126 277.1)
-
Step 500
500
#737CE8
oklch(63% 0.16 277.2)
-
Step 600
600
#5D62D7
oklch(55.5% 0.176 277.2)
-
Step 700
700
#4D51BA
oklch(49.1% 0.162 277)
-
Step 800
800
#3F4397
oklch(42.8% 0.135 277)
-
Step 900
900
#353978
oklch(37.6% 0.106 277.3)
-
Step 950
950 (this color)
#15173A
oklch(22.5% 0.066 277.2)
#15173A with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #051C3B | 0.024 |
| Deuteranopia (no green cones) | #021939 | 0.026 |
| Tritanopia (no blue cones) | #041F25 | 0.059 |
| Achromatopsia (no color) | #1B1B1B | 0.067 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #15173A
#15173A
oklch(22.5% 0.066 277.2)
- #221C00
#221C00
oklch(22.7% 0.047 98)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #15173A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.039
- Navy Blue #001146 ΔE 0.044
- Oxford Blue #1B263B ΔE 0.052
- Dark #1B2431 ΔE 0.053
- Dark Indigo #1F0954 ΔE 0.059
- Midnight Purple #280137 ΔE 0.064
- Night Blue #040348 ΔE 0.065
- Very Dark Purple #2A0134 ΔE 0.068
Use #15173A in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.