#101221
Closest named color: Rich Black (#0D1B2A). oklch(18.8% 0.031 277.2), rgb(16, 18, 33).
Aa
White text reads best on this color (18.57:1).
About this color
#101221 is a very dark, muted blue. In OKLCH its lightness is 19%, its chroma 0.031 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.033 away. White text reads best on it, at 18.57:1.
| Hue family | Blues |
| Lightness | very dark (19%) |
| Chroma | muted (0.031) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.13:1 |
| White text | 18.57:1 |
Values
| HEX | #101221 |
| RGB | rgb(16, 18, 33) |
| HSL | hsl(233, 35%, 10%) |
| OKLCH | oklch(18.8% 0.031 277.2) |
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 #101221 | 18.57:1 | AAA | Lc -107.2 | Preferred for body text |
| Black text on #101221 | 1.13:1 | Fails | Lc 0.0 | Not readable |
| #101221 text on white | 18.57:1 | AAA | Lc 105.1 | Preferred for body text |
| #101221 text on black | 1.13:1 | 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
#F4F5F9
oklch(97.1% 0.005 275)
-
Step 100
100
#E8E9F1
oklch(93.6% 0.011 280.5)
-
Step 200
200
#D5D8E7
oklch(88.4% 0.021 276.9)
-
Step 300
300
#BABFD9
oklch(80.9% 0.037 276.9)
-
Step 400
400
#979EC5
oklch(70.7% 0.058 276.9)
-
Step 500
500
#7E86B6
oklch(63.2% 0.073 276.8)
-
Step 600
600
#676FA2
oklch(55.6% 0.08 276.6)
-
Step 700
700
#565C8B
oklch(49% 0.076 277.7)
-
Step 800
800
#464C71
oklch(42.8% 0.062 276.4)
-
Step 900
900
#3B3F5B
oklch(37.6% 0.048 277.5)
-
Step 950
950 (this color)
#101221
oklch(18.8% 0.031 277.2)
#101221 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) | #0D1422 | 0.008 |
| Deuteranopia (no green cones) | #0C1221 | 0.007 |
| Tritanopia (no blue cones) | #0B1517 | 0.028 |
| Achromatopsia (no color) | #131313 | 0.031 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #101221
#101221
oklch(18.8% 0.031 277.2)
- #171304
#171304
oklch(18.7% 0.029 95.9)
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 #101221, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.033
- Rich Navy #001219 ΔE 0.034
- Almost Black #070D0D ΔE 0.047
- Dark #1B2431 ΔE 0.070
- Dark Navy #000435 ΔE 0.072
- Midnight #03012D ΔE 0.074
- Dark Navy Blue #00022E ΔE 0.075
- Navy Blue #001146 ΔE 0.076
Use #101221 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.