#21377A
Closest named color: Twilight Blue (#0A437A). oklch(36.1% 0.118 266.7), rgb(33, 55, 122).
Aa
White text reads best on this color (11.09:1).
About this color
#21377A is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.118 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.035 away. White text reads best on it, at 11.09:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.118) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.89:1 |
| White text | 11.09:1 |
Values
| HEX | #21377A |
| RGB | rgb(33, 55, 122) |
| HSL | hsl(225, 57%, 30%) |
| OKLCH | oklch(36.1% 0.118 266.7) |
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 #21377A | 11.09:1 | AAA | Lc -99.2 | Preferred for body text |
| Black text on #21377A | 1.89:1 | Fails | Lc 8.6 | Not readable |
| #21377A text on white | 11.09:1 | AAA | Lc 95.3 | Preferred for body text |
| #21377A text on black | 1.89:1 | Fails | Lc -7.3 | 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 900.
-
Step 50
50
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E2EAFC
oklch(93.6% 0.026 266.6)
-
Step 200
200
#CAD9FB
oklch(88.5% 0.05 266.5)
-
Step 300
300
#A7C0FA
oklch(81% 0.087 266.4)
-
Step 400
400
#789CF8
oklch(70.6% 0.141 266.7)
-
Step 500
500
#5880F5
oklch(63% 0.18 267)
-
Step 600
600
#3F66E4
oklch(55.5% 0.196 266.8)
-
Step 700
700
#3254C6
oklch(49.1% 0.182 266.8)
-
Step 800
800
#2946A0
oklch(42.8% 0.15 266.5)
-
Step 900
900 (this color)
#21377A
oklch(36.1% 0.118 266.7)
-
Step 950
950
#16244A
oklch(27.1% 0.073 266.4)
#21377A 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) | #09407C | 0.028 |
| Deuteranopia (no green cones) | #003879 | 0.024 |
| Tritanopia (no blue cones) | #004753 | 0.094 |
| Achromatopsia (no color) | #3C3C3C | 0.118 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21377A
#21377A
oklch(36.1% 0.118 266.7)
- #4E3A00
#4E3A00
oklch(36.1% 0.074 86.8)
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 #21377A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.035
- Marine Blue #01386A ΔE 0.038
- Cobalt #1E488F ΔE 0.056
- Marine #042E60 ΔE 0.060
- Prussian Blue #1D3557 ΔE 0.061
- Dark Slate Blue #483D8B ΔE 0.068
- Light Navy #155084 ΔE 0.071
- Blueberry #464196 ΔE 0.077
Use #21377A 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.