#304B59
Closest named color: Dark Grey Blue (#29465B). oklch(39.7% 0.04 231.7), rgb(48, 75, 89).
Aa
White text reads best on this color (9.22:1).
About this color
#304B59 is a dark, muted blue. In OKLCH its lightness is 40%, its chroma 0.040 and its hue 232°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.020 away. White text reads best on it, at 9.22:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | muted (0.040) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 2.27:1 |
| White text | 9.22:1 |
Values
| HEX | #304B59 |
| RGB | rgb(48, 75, 89) |
| HSL | hsl(200, 30%, 27%) |
| OKLCH | oklch(39.7% 0.04 231.7) |
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 #304B59 | 9.22:1 | AAA | Lc -95.6 | Preferred for body text |
| Black text on #304B59 | 2.27:1 | Fails | Lc 12.7 | Not readable |
| #304B59 text on white | 9.22:1 | AAA | Lc 91.2 | Preferred for body text |
| #304B59 text on black | 2.27:1 | Fails | Lc -11.1 | 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
#E4EBEF
oklch(93.6% 0.009 232.4)
-
Step 200
200
#CFDBE2
oklch(88.4% 0.016 233)
-
Step 300
300
#AEC5D1
oklch(81% 0.03 230.4)
-
Step 400
400
#83A7BA
oklch(70.8% 0.048 231.3)
-
Step 500
500
#6291A9
oklch(63.2% 0.062 231.2)
-
Step 600
600
#487A94
oklch(55.5% 0.067 232.5)
-
Step 700
700
#39677E
oklch(49.1% 0.063 231.7)
-
Step 800
800
#305467
oklch(42.7% 0.052 232.9)
-
Step 900
900 (this color)
#304B59
oklch(39.7% 0.04 231.7)
-
Step 950
950
#192931
oklch(27% 0.026 230.6)
#304B59 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) | #444A5A | 0.028 |
| Deuteranopia (no green cones) | #3E4559 | 0.026 |
| Tritanopia (no blue cones) | #1F4F4F | 0.031 |
| Achromatopsia (no color) | #474747 | 0.040 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #304B59
#304B59
oklch(39.7% 0.04 231.7)
- #594133
#594133
oklch(39.8% 0.04 51.5)
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 #304B59, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.020
- Charcoal #264653 ΔE 0.023
- Dark Slate Gray #2F4F4F ΔE 0.025
- Deep Teal #00555A ΔE 0.042
- Dark Teal #014D4E ΔE 0.043
- Charcoal Grey #3C4142 ΔE 0.043
- Dark Blue Green #005249 ΔE 0.054
- Dark Blue Grey #1F3B4D ΔE 0.059
Use #304B59 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.