#233F8C
Closest named color: Cobalt (#1E488F). oklch(39.4% 0.133 265.5), rgb(35, 63, 140).
Aa
White text reads best on this color (9.71:1).
About this color
#233F8C is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.133 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 9.71:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.133) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.16:1 |
| White text | 9.71:1 |
Values
| HEX | #233F8C |
| RGB | rgb(35, 63, 140) |
| HSL | hsl(224, 60%, 34%) |
| OKLCH | oklch(39.4% 0.133 265.5) |
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 #233F8C | 9.71:1 | AAA | Lc -96.4 | Preferred for body text |
| Black text on #233F8C | 2.16:1 | Fails | Lc 11.8 | Not readable |
| #233F8C text on white | 9.71:1 | AAA | Lc 92.1 | Preferred for body text |
| #233F8C text on black | 2.16:1 | Fails | Lc -10.3 | 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
#F1F6FF
oklch(97.2% 0.013 262.4)
-
Step 100
100
#E1EAFE
oklch(93.6% 0.029 266.4)
-
Step 200
200
#C8D9FF
oklch(88.5% 0.056 266.2)
-
Step 300
300
#A3C0FF
oklch(80.9% 0.095 265.2)
-
Step 400
400
#739CFF
oklch(70.7% 0.152 265.7)
-
Step 500
500
#4F7FFF
oklch(63.1% 0.197 265.6)
-
Step 600
600
#3463F2
oklch(55.7% 0.221 265.6)
-
Step 700
700
#2750D3
oklch(49% 0.206 265.6)
-
Step 800
800
#2143AA
oklch(42.7% 0.17 265.5)
-
Step 900
900 (this color)
#233F8C
oklch(39.4% 0.133 265.5)
-
Step 950
950
#12234F
oklch(27% 0.084 265.3)
#233F8C 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) | #04498F | 0.030 |
| Deuteranopia (no green cones) | #00408A | 0.022 |
| Tritanopia (no blue cones) | #00525F | 0.106 |
| Achromatopsia (no color) | #444444 | 0.133 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #233F8C
#233F8C
oklch(39.4% 0.133 265.5)
- #594200
#594200
oklch(39.3% 0.081 86)
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 #233F8C, 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 0.038
- Dark Slate Blue #483D8B ΔE 0.051
- Blueberry #464196 ΔE 0.051
- Light Navy #155084 ΔE 0.052
- Sapphire #2138AB ΔE 0.054
- Dusk Blue #26538D ΔE 0.057
- Deep Sea Blue #015482 ΔE 0.065
Use #233F8C 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.