#304257
Closest named color: Dark Grey Blue (#29465B). oklch(37.3% 0.043 252.8), rgb(48, 66, 87).
Aa
White text reads best on this color (10.28:1).
About this color
#304257 is a dark, muted blue. In OKLCH its lightness is 37%, its chroma 0.043 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.014 away. White text reads best on it, at 10.28:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | muted (0.043) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 2.04:1 |
| White text | 10.28:1 |
Values
| HEX | #304257 |
| RGB | rgb(48, 66, 87) |
| HSL | hsl(212, 29%, 26%) |
| OKLCH | oklch(37.3% 0.043 252.8) |
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 #304257 | 10.28:1 | AAA | Lc -97.9 | Preferred for body text |
| Black text on #304257 | 2.04:1 | Fails | Lc 10.1 | Not readable |
| #304257 text on white | 10.28:1 | AAA | Lc 93.8 | Preferred for body text |
| #304257 text on black | 2.04:1 | Fails | Lc -8.7 | 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
#F3F6F8
oklch(97.1% 0.004 236.5)
-
Step 100
100
#E6EAF0
oklch(93.6% 0.009 258.3)
-
Step 200
200
#D1DAE5
oklch(88.5% 0.018 253.4)
-
Step 300
300
#B2C2D5
oklch(80.8% 0.032 252.7)
-
Step 400
400
#8AA3C1
oklch(70.7% 0.052 253.2)
-
Step 500
500
#6D8CB1
oklch(63.1% 0.066 253.2)
-
Step 600
600
#55769D
oklch(55.7% 0.072 253.1)
-
Step 700
700
#456386
oklch(49.1% 0.067 252.9)
-
Step 800
800
#39516D
oklch(42.8% 0.055 252.9)
-
Step 900
900 (this color)
#304257
oklch(37.3% 0.043 252.8)
-
Step 950
950
#1D2734
oklch(26.9% 0.028 255.2)
#304257 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) | #3A4358 | 0.015 |
| Deuteranopia (no green cones) | #353F57 | 0.011 |
| Tritanopia (no blue cones) | #224749 | 0.038 |
| Achromatopsia (no color) | #414141 | 0.043 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #304257
#304257
oklch(37.3% 0.043 252.8)
- #4F3D26
#4F3D26
oklch(37.3% 0.044 72.6)
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 #304257, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.014
- Charcoal #264653 ΔE 0.020
- Dark Blue Grey #1F3B4D ΔE 0.036
- Charcoal Grey #3C4142 ΔE 0.038
- Onyx #343A40 ΔE 0.041
- Dark Slate Gray #2F4F4F ΔE 0.049
- Prussian Blue #1D3557 ΔE 0.052
- Midnight Green #073B4C ΔE 0.052
Use #304257 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.