#CB2403
Closest named color: Sinopia (#BB3E03). oklch(54.3% 0.204 32), rgb(203, 36, 3).
Aa
White text reads best on this color (5.53:1).
About this color
#CB2403 is a medium-dark, vivid red. In OKLCH its lightness is 54%, its chroma 0.204 and its hue 32°. Its hue sits on the warm side of the wheel. The nearest named color is Sinopia (#BB3E03), ΔE 0.041 away. White text reads best on it, at 5.53:1.
| Hue family | Reds |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.204) |
| Temperature | warm |
| Nearest name | Sinopia (#BB3E03) |
| Black text | 3.79:1 |
| White text | 5.53:1 |
Values
| HEX | #CB2403 |
| RGB | rgb(203, 36, 3) |
| HSL | hsl(10, 97%, 40%) |
| OKLCH | oklch(54.3% 0.204 32) |
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 #CB2403 | 5.53:1 | AA | Lc -81.1 | Fine for body text |
| Black text on #CB2403 | 3.79:1 | AA large text | Lc 28.3 | Dividers and decoration only |
| #CB2403 text on white | 5.53:1 | AA | Lc 75.7 | Fine for body text |
| #CB2403 text on black | 3.79:1 | AA large text | Lc -26.0 | Dividers and decoration only |
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 600.
-
Step 50
50
#FEF3F0
oklch(97.2% 0.013 35.7)
-
Step 100
100
#FBE4DF
oklch(93.6% 0.026 32.2)
-
Step 200
200
#F9CEC4
oklch(88.6% 0.051 33.3)
-
Step 300
300
#F6AB9C
oklch(80.9% 0.092 31.7)
-
Step 400
400
#EE7A64
oklch(70.7% 0.148 32.1)
-
Step 500
500
#E45138
oklch(63.1% 0.187 32.1)
-
Step 600
600 (this color)
#CB2403
oklch(54.3% 0.204 32)
-
Step 700
700
#B21D00
oklch(49.1% 0.186 32)
-
Step 800
800
#921A05
oklch(42.8% 0.158 32)
-
Step 900
900
#751F11
oklch(37.8% 0.122 31.9)
-
Step 950
950
#45140C
oklch(27% 0.077 31.7)
#CB2403 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) | #5D5100 | 0.218 |
| Deuteranopia (no green cones) | #857500 | 0.194 |
| Tritanopia (no blue cones) | #E00021 | 0.046 |
| Achromatopsia (no color) | #686868 | 0.206 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #CB2403
#CB2403
oklch(54.3% 0.204 32)
- #007D8F
#007D8F
oklch(54.1% 0.094 212.2)
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 #CB2403, closest first.
No curated palette has a color within ΔE 0.04 of #CB2403.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sinopia #BB3E03 ΔE 0.041
- Scarlet #BE0119 ΔE 0.044
- Cherry #CF0234 ΔE 0.044
- Dull Red #BB3F3F ΔE 0.051
- Lipstick Red #C0022F ΔE 0.051
- Brick Orange #C14A09 ΔE 0.054
- Rusty Red #AF2F0D ΔE 0.055
- Firebrick #B22222 ΔE 0.055
Use #CB2403 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.