#233F8F
Closest named color: Cobalt (#1E488F). oklch(39.6% 0.137 265.8), rgb(35, 63, 143).
Aa
White text reads best on this color (9.63:1).
About this color
#233F8F is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.137 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.024 away. White text reads best on it, at 9.63:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.137) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.17:1 |
| White text | 9.63:1 |
Values
| HEX | #233F8F |
| RGB | rgb(35, 63, 143) |
| HSL | hsl(224, 61%, 35%) |
| OKLCH | oklch(39.6% 0.137 265.8) |
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 #233F8F | 9.63:1 | AAA | Lc -96.2 | Preferred for body text |
| Black text on #233F8F | 2.17:1 | Fails | Lc 12.1 | Not readable |
| #233F8F text on white | 9.63:1 | AAA | Lc 91.9 | Preferred for body text |
| #233F8F text on black | 2.17:1 | Fails | Lc -10.5 | 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
#F1F5FF
oklch(97% 0.014 268.5)
-
Step 100
100
#E0EAFF
oklch(93.6% 0.03 265.3)
-
Step 200
200
#C8D9FF
oklch(88.5% 0.056 266.2)
-
Step 300
300
#A4C0FF
oklch(81% 0.095 265.8)
-
Step 400
400
#739CFF
oklch(70.7% 0.152 265.7)
-
Step 500
500
#507FFF
oklch(63.1% 0.197 265.8)
-
Step 600
600
#3361F6
oklch(55.6% 0.228 265.8)
-
Step 700
700
#274FD6
oklch(49.1% 0.211 265.8)
-
Step 800
800
#2042AD
oklch(42.7% 0.175 265.6)
-
Step 900
900 (this color)
#233F8F
oklch(39.6% 0.137 265.8)
-
Step 950
950
#122250
oklch(26.9% 0.087 266.2)
#233F8F 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) | #004A92 | 0.032 |
| Deuteranopia (no green cones) | #00408D | 0.022 |
| Tritanopia (no blue cones) | #005360 | 0.110 |
| Achromatopsia (no color) | #454545 | 0.137 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #233F8F
#233F8F
oklch(39.6% 0.137 265.8)
- #5A4300
#5A4300
oklch(39.7% 0.081 86.3)
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 #233F8F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.024
- Twilight Blue #0A437A ΔE 0.042
- Sapphire #2138AB ΔE 0.049
- Blueberry #464196 ΔE 0.050
- Dark Slate Blue #483D8B ΔE 0.051
- Light Navy #155084 ΔE 0.053
- Dusk Blue #26538D ΔE 0.058
- Deep Sea Blue #015482 ΔE 0.067
Use #233F8F 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.