#233C8F
Closest named color: Cobalt (#1E488F). oklch(39% 0.141 266.9), rgb(35, 60, 143).
Aa
White text reads best on this color (9.93:1).
About this color
#233C8F is a dark, vivid blue. In OKLCH its lightness is 39%, its chroma 0.141 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.032 away. White text reads best on it, at 9.93:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | vivid (0.141) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.11:1 |
| White text | 9.93:1 |
Values
| HEX | #233C8F |
| RGB | rgb(35, 60, 143) |
| HSL | hsl(226, 61%, 35%) |
| OKLCH | oklch(39% 0.141 266.9) |
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 #233C8F | 9.93:1 | AAA | Lc -96.8 | Preferred for body text |
| Black text on #233C8F | 2.11:1 | Fails | Lc 11.4 | Not readable |
| #233C8F text on white | 9.93:1 | AAA | Lc 92.6 | Preferred for body text |
| #233C8F text on black | 2.11:1 | Fails | Lc -9.9 | 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
#E1EAFF
oklch(93.7% 0.03 267.2)
-
Step 200
200
#C9D9FF
oklch(88.6% 0.055 267.2)
-
Step 300
300
#A5BFFF
oklch(80.9% 0.095 267.2)
-
Step 400
400
#769BFF
oklch(70.7% 0.152 267.2)
-
Step 500
500
#537EFF
oklch(63.1% 0.197 266.8)
-
Step 600
600
#365FFA
oklch(55.7% 0.235 266.7)
-
Step 700
700
#2A4CDA
oklch(49.1% 0.219 266.9)
-
Step 800
800
#2340B0
oklch(42.7% 0.181 266.8)
-
Step 900
900 (this color)
#233C8F
oklch(39% 0.141 266.9)
-
Step 950
950
#132251
oklch(27% 0.088 267)
#233C8F 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) | #004892 | 0.034 |
| Deuteranopia (no green cones) | #003E8D | 0.023 |
| Tritanopia (no blue cones) | #00515F | 0.113 |
| Achromatopsia (no color) | #434343 | 0.141 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #233C8F
#233C8F
oklch(39% 0.141 266.9)
- #574100
#574100
oklch(38.9% 0.079 86.8)
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 #233C8F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.032
- Twilight Blue #0A437A ΔE 0.045
- Sapphire #2138AB ΔE 0.047
- Blueberry #464196 ΔE 0.053
- Dark Slate Blue #483D8B ΔE 0.053
- Light Navy #155084 ΔE 0.061
- Dusk Blue #26538D ΔE 0.066
- Marine Blue #01386A ΔE 0.071
Use #233C8F 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.