#C73B03
Closest named color: Sinopia (#BB3E03). oklch(55.5% 0.184 37), rgb(199, 59, 3).
Aa
White text reads best on this color (5.17:1).
About this color
#C73B03 is a medium-dark, vivid red. In OKLCH its lightness is 56%, its chroma 0.184 and its hue 37°. Its hue sits on the warm side of the wheel. The nearest named color is Sinopia (#BB3E03), ΔE 0.023 away. White text reads best on it, at 5.17:1.
| Hue family | Reds |
| Lightness | medium-dark (56%) |
| Chroma | vivid (0.184) |
| Temperature | warm |
| Nearest name | Sinopia (#BB3E03) |
| Black text | 4.05:1 |
| White text | 5.17:1 |
Values
| HEX | #C73B03 |
| RGB | rgb(199, 59, 3) |
| HSL | hsl(17, 97%, 40%) |
| OKLCH | oklch(55.5% 0.184 37) |
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 #C73B03 | 5.17:1 | AA | Lc -79.7 | Fine for body text |
| Black text on #C73B03 | 4.05:1 | AA large text | Lc 29.7 | Dividers and decoration only |
| #C73B03 text on white | 5.17:1 | AA | Lc 74.3 | Content text, not long reading |
| #C73B03 text on black | 4.05:1 | AA large text | Lc -27.4 | 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
#FDF3F0
oklch(97.1% 0.012 37.4)
-
Step 100
100
#F9E5DF
oklch(93.6% 0.023 37.4)
-
Step 200
200
#F6CFC4
oklch(88.5% 0.047 36.3)
-
Step 300
300
#F1AE9B
oklch(80.9% 0.084 36.5)
-
Step 400
400
#E68063
oklch(70.6% 0.133 36.7)
-
Step 500
500
#DC5B35
oklch(63.1% 0.17 36.9)
-
Step 600
600 (this color)
#C73B03
oklch(55.5% 0.184 37)
-
Step 700
700
#A93000
oklch(49.1% 0.164 37)
-
Step 800
800
#8C2701
oklch(42.8% 0.142 37.1)
-
Step 900
900
#70260F
oklch(37.7% 0.11 37)
-
Step 950
950
#42170B
oklch(26.9% 0.07 36.4)
#C73B03 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) | #665900 | 0.188 |
| Deuteranopia (no green cones) | #887800 | 0.169 |
| Tritanopia (no blue cones) | #DC0033 | 0.070 |
| Achromatopsia (no color) | #6D6D6D | 0.186 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #C73B03
#C73B03
oklch(55.5% 0.184 37)
- #008199
#008199
oklch(55.6% 0.099 216.9)
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 #C73B03, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sinopia #BB3E03 ΔE 0.023
- Brick Orange #C14A09 ΔE 0.026
- Burnt Orange #C04E01 ΔE 0.034
- Rust Orange #C45508 ΔE 0.046
- Dull Red #BB3F3F ΔE 0.047
- Burnt Siena #B75203 ΔE 0.048
- Deep Orange #DC4D01 ΔE 0.056
- Rusty Red #AF2F0D ΔE 0.057
Use #C73B03 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.