#EF663A
Closest named color: Burnt Sienna (#E76F51). oklch(67.5% 0.179 37.9), rgb(239, 102, 58).
Aa
Black text reads best on this color (6.63:1).
About this color
#EF663A is a medium-light, vivid red. In OKLCH its lightness is 67%, its chroma 0.179 and its hue 38°. Its hue sits on the warm side of the wheel. The nearest named color is Burnt Sienna (#E76F51), ΔE 0.025 away. Black text reads best on it, at 6.63:1.
| Hue family | Reds |
| Lightness | medium-light (67%) |
| Chroma | vivid (0.179) |
| Temperature | warm |
| Nearest name | Burnt Sienna (#E76F51) |
| Black text | 6.63:1 |
| White text | 3.16:1 |
Values
| HEX | #EF663A |
| RGB | rgb(239, 102, 58) |
| HSL | hsl(15, 85%, 58%) |
| OKLCH | oklch(67.5% 0.179 37.9) |
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 #EF663A | 3.16:1 | AA large text | Lc -63.4 | Content text, not long reading |
| Black text on #EF663A | 6.63:1 | AA | Lc 46.0 | Large or bold text, headings |
| #EF663A text on white | 3.16:1 | AA large text | Lc 58.0 | Large or bold text, headings |
| #EF663A text on black | 6.63:1 | AA | Lc -43.7 | Non-text elements, placeholder text |
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 400.
-
Step 50
50
#FFF2EE
oklch(97% 0.015 37.9)
-
Step 100
100
#FEE3DB
oklch(93.6% 0.032 37.1)
-
Step 200
200
#FFCCBC
oklch(88.6% 0.062 38.1)
-
Step 300
300
#FFA78C
oklch(80.9% 0.111 37.8)
-
Step 400
400 (this color)
#EF663A
oklch(67.5% 0.179 37.9)
-
Step 500
500
#EB4A00
oklch(63.1% 0.207 37.9)
-
Step 600
600
#C63D00
oklch(55.5% 0.182 37.9)
-
Step 700
700
#A83200
oklch(49.1% 0.162 37.8)
-
Step 800
800
#8B2800
oklch(42.8% 0.14 37.9)
-
Step 900
900
#752000
oklch(37.7% 0.124 37.7)
-
Step 950
950
#481000
oklch(26.9% 0.089 37.6)
#EF663A 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) | #8C7E34 | 0.178 |
| Deuteranopia (no green cones) | #AE9C36 | 0.162 |
| Tritanopia (no blue cones) | #FF475D | 0.076 |
| Achromatopsia (no color) | #919191 | 0.180 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #EF663A
#EF663A
oklch(67.5% 0.179 37.9)
- #00A8C8
#00A8C8
oklch(67.5% 0.121 217.8)
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 #EF663A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Burnt Sienna #E76F51 ΔE 0.025
- Tomato #FF6347 ΔE 0.033
- Orange Pant #FB5607 ΔE 0.034
- Bright Orange #FF5B00 ΔE 0.035
- Orange Pink #FF6F52 ΔE 0.041
- Pinkish Orange #FF724C ΔE 0.042
- Blood Orange #FE4B03 ΔE 0.046
- Grapefruit #FD5956 ΔE 0.048
Use #EF663A 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.