#21406A
Closest named color: Twilight Blue (#0A437A). oklch(37% 0.082 256.5), rgb(33, 64, 106).
Aa
White text reads best on this color (10.46:1).
About this color
#21406A is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.082 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.030 away. White text reads best on it, at 10.46:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.082) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.00:1 |
| White text | 10.46:1 |
Values
| HEX | #21406A |
| RGB | rgb(33, 64, 106) |
| HSL | hsl(215, 53%, 27%) |
| OKLCH | oklch(37% 0.082 256.5) |
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 #21406A | 10.46:1 | AAA | Lc -98.1 | Preferred for body text |
| Black text on #21406A | 2.00:1 | Fails | Lc 9.8 | Not readable |
| #21406A text on white | 10.46:1 | AAA | Lc 94.1 | Preferred for body text |
| #21406A text on black | 2.00:1 | Fails | Lc -8.5 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E2EBF6
oklch(93.7% 0.018 253.3)
-
Step 200
200
#CBDBF0
oklch(88.6% 0.034 255.2)
-
Step 300
300
#A8C3E8
oklch(81% 0.06 256.3)
-
Step 400
400
#78A3DD
oklch(70.7% 0.098 256.1)
-
Step 500
500
#558BD4
oklch(63.2% 0.125 256.4)
-
Step 600
600
#3973C1
oklch(55.6% 0.136 256.6)
-
Step 700
700
#2B60A7
oklch(49.1% 0.127 256.7)
-
Step 800
800
#254F87
oklch(42.7% 0.104 256.5)
-
Step 900
900 (this color)
#21406A
oklch(37% 0.082 256.5)
-
Step 950
950
#15273F
oklch(27% 0.051 256.1)
#21406A 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) | #2D436C | 0.018 |
| Deuteranopia (no green cones) | #233C69 | 0.012 |
| Tritanopia (no blue cones) | #004A50 | 0.066 |
| Achromatopsia (no color) | #3F3F3F | 0.082 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21406A
#21406A
oklch(37% 0.082 256.5)
- #573900
#573900
oklch(37% 0.078 75.9)
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 #21406A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.030
- Marine Blue #01386A ΔE 0.037
- Dark Grey Blue #29465B ΔE 0.037
- Prussian Blue #1D3557 ΔE 0.045
- Charcoal #264653 ΔE 0.049
- Dark Blue Grey #1F3B4D ΔE 0.051
- Light Navy #155084 ΔE 0.058
- Midnight Green #073B4C ΔE 0.059
Use #21406A 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.