#12173B
Closest named color: Rich Black (#0D1B2A). oklch(22.4% 0.069 273.5), rgb(18, 23, 59).
Aa
White text reads best on this color (17.33:1).
About this color
#12173B is a very dark, muted blue. In OKLCH its lightness is 22%, its chroma 0.069 and its hue 274°. 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 17.33:1.
| Hue family | Blues |
| Lightness | very dark (22%) |
| Chroma | muted (0.069) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.21:1 |
| White text | 17.33:1 |
Values
| HEX | #12173B |
| RGB | rgb(18, 23, 59) |
| HSL | hsl(233, 53%, 15%) |
| OKLCH | oklch(22.4% 0.069 273.5) |
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 #12173B | 17.33:1 | AAA | Lc -106.4 | Preferred for body text |
| Black text on #12173B | 1.21:1 | Fails | Lc 0.0 | Not readable |
| #12173B text on white | 17.33:1 | AAA | Lc 104.1 | Preferred for body text |
| #12173B 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
#E4E9FA
oklch(93.5% 0.024 272.8)
-
Step 200
200
#CFD8F8
oklch(88.5% 0.045 273)
-
Step 300
300
#AFBDF6
oklch(80.8% 0.082 273.7)
-
Step 400
400
#879AF2
oklch(70.8% 0.131 273.4)
-
Step 500
500
#6B7EED
oklch(63.2% 0.167 273.4)
-
Step 600
600
#5564DB
oklch(55.6% 0.181 273.6)
-
Step 700
700
#4552BE
oklch(49.1% 0.168 273.3)
-
Step 800
800
#39449A
oklch(42.8% 0.14 273.5)
-
Step 900
900
#303A7A
oklch(37.6% 0.109 273.4)
-
Step 950
950 (this color)
#12173B
oklch(22.4% 0.069 273.5)
#12173B 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) | #031C3C | 0.022 |
| Deuteranopia (no green cones) | #00193A | 0.024 |
| Tritanopia (no blue cones) | #001F26 | 0.059 |
| Achromatopsia (no color) | #1A1A1A | 0.069 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #12173B
#12173B
oklch(22.4% 0.069 273.5)
- #231B00
#231B00
oklch(22.5% 0.046 93.6)
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 #12173B, 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 0.039
- Oxford Blue #1B263B ΔE 0.054
- Dark #1B2431 ΔE 0.055
- Dark Indigo #1F0954 ΔE 0.058
- Night Blue #040348 ΔE 0.061
- Midnight Purple #280137 ΔE 0.068
- Dark Navy #000435 ΔE 0.071
Use #12173B 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.