#21306B
Closest named color: Marine Blue (#01386A). oklch(33.3% 0.104 269.3), rgb(33, 48, 107).
Aa
White text reads best on this color (12.35:1).
About this color
#21306B is a dark, moderately saturated blue. In OKLCH its lightness is 33%, its chroma 0.104 and its hue 269°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.031 away. White text reads best on it, at 12.35:1.
| Hue family | Blues |
| Lightness | dark (33%) |
| Chroma | moderately saturated (0.104) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.69:1 |
| White text | 12.35:1 |
Values
| HEX | #21306B |
| RGB | rgb(33, 48, 107) |
| HSL | hsl(228, 53%, 27%) |
| OKLCH | oklch(33.3% 0.104 269.3) |
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 #21306B | 12.35:1 | AAA | Lc -101.3 | Preferred for body text |
| Black text on #21306B | 1.69:1 | Fails | Lc 0.0 | Not readable |
| #21306B text on white | 12.35:1 | AAA | Lc 97.8 | Preferred for body text |
| #21306B text on black | 1.69:1 | 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 900.
-
Step 50
50
#F2F5FD
oklch(97% 0.011 269.6)
-
Step 100
100
#E4EAFA
oklch(93.7% 0.023 269.4)
-
Step 200
200
#CDD9F7
oklch(88.6% 0.043 268.2)
-
Step 300
300
#ACBFF4
oklch(80.9% 0.078 269.3)
-
Step 400
400
#819CEF
oklch(70.7% 0.126 269.3)
-
Step 500
500
#6381E9
oklch(63.1% 0.16 269.3)
-
Step 600
600
#4B68D8
oklch(55.6% 0.175 269.1)
-
Step 700
700
#3D56BB
oklch(49.2% 0.161 269.2)
-
Step 800
800
#324797
oklch(42.7% 0.133 269)
-
Step 900
900 (this color)
#21306B
oklch(33.3% 0.104 269.3)
-
Step 950
950
#192447
oklch(27.1% 0.067 268.5)
#21306B 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) | #0B386D | 0.027 |
| Deuteranopia (no green cones) | #00316A | 0.028 |
| Tritanopia (no blue cones) | #003E48 | 0.087 |
| Achromatopsia (no color) | #353535 | 0.105 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21306B
#21306B
oklch(33.3% 0.104 269.3)
- #443400
#443400
oklch(33.3% 0.068 89.7)
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 #21306B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.031
- Marine #042E60 ΔE 0.035
- Prussian Blue #1D3557 ΔE 0.041
- Twilight Blue #0A437A ΔE 0.057
- Midnight Blue #191970 ΔE 0.060
- Dark Blue Grey #1F3B4D ΔE 0.069
- Space Cadet #2B2D42 ΔE 0.073
- Midnight Green #073B4C ΔE 0.074
Use #21306B 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.