#21457C
Closest named color: Twilight Blue (#0A437A). oklch(39.4% 0.102 258.7), rgb(33, 69, 124).
Aa
White text reads best on this color (9.51:1).
About this color
#21457C is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.102 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.018 away. White text reads best on it, at 9.51:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.20:1 |
| White text | 9.51:1 |
Values
| HEX | #21457C |
| RGB | rgb(33, 69, 124) |
| HSL | hsl(216, 58%, 31%) |
| OKLCH | oklch(39.4% 0.102 258.7) |
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 #21457C | 9.51:1 | AAA | Lc -96.0 | Preferred for body text |
| Black text on #21457C | 2.20:1 | Fails | Lc 12.2 | Not readable |
| #21457C text on white | 9.51:1 | AAA | Lc 91.7 | Preferred for body text |
| #21457C text on black | 2.20:1 | Fails | Lc -10.6 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E1EBF9
oklch(93.7% 0.022 256.7)
-
Step 200
200
#C8DAF6
oklch(88.4% 0.043 259.2)
-
Step 300
300
#A3C2F3
oklch(80.9% 0.077 259.4)
-
Step 400
400
#71A1EC
oklch(70.6% 0.122 259)
-
Step 500
500
#4A88E6
oklch(63.1% 0.156 258.6)
-
Step 600
600
#2C6FD5
oklch(55.6% 0.171 259)
-
Step 700
700
#1E5DB8
oklch(49.2% 0.157 258.5)
-
Step 800
800
#1B4C95
oklch(42.7% 0.131 258.7)
-
Step 900
900 (this color)
#21457C
oklch(39.4% 0.102 258.7)
-
Step 950
950
#112646
oklch(27% 0.066 258.6)
#21457C 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) | #2B4A7E | 0.020 |
| Deuteranopia (no green cones) | #1B427B | 0.011 |
| Tritanopia (no blue cones) | #00525A | 0.082 |
| Achromatopsia (no color) | #454545 | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21457C
#21457C
oklch(39.4% 0.102 258.7)
- #5E4000
#5E4000
oklch(39.5% 0.082 78.6)
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 #21457C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.018
- Cobalt #1E488F ΔE 0.032
- Light Navy #155084 ΔE 0.033
- Deep Sea Blue #015482 ΔE 0.044
- Dusk Blue #26538D ΔE 0.048
- Marine Blue #01386A ΔE 0.056
- Dark Grey Blue #29465B ΔE 0.058
- Dark Slate Blue #483D8B ΔE 0.061
Use #21457C 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.