#EF3F17
Closest named color: Vermillion (#F4320C). oklch(62.8% 0.218 33.4), rgb(239, 63, 23).
Aa
Black text reads best on this color (5.39:1).
About this color
#EF3F17 is a medium-light, vivid red. In OKLCH its lightness is 63%, its chroma 0.218 and its hue 33°. Its hue sits on the warm side of the wheel. The nearest named color is Vermillion (#F4320C), ΔE 0.015 away. Black text reads best on it, at 5.39:1.
| Hue family | Reds |
| Lightness | medium-light (63%) |
| Chroma | vivid (0.218) |
| Temperature | warm |
| Nearest name | Vermillion (#F4320C) |
| Black text | 5.39:1 |
| White text | 3.89:1 |
Values
| HEX | #EF3F17 |
| RGB | rgb(239, 63, 23) |
| HSL | hsl(11, 87%, 51%) |
| OKLCH | oklch(62.8% 0.218 33.4) |
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 #EF3F17 | 3.89:1 | AA large text | Lc -70.3 | Content text, not long reading |
| Black text on #EF3F17 | 5.39:1 | AA | Lc 39.3 | Non-text elements, placeholder text |
| #EF3F17 text on white | 3.89:1 | AA large text | Lc 64.8 | Content text, not long reading |
| #EF3F17 text on black | 5.39:1 | AA | Lc -36.8 | 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 500.
-
Step 50
50
#FFF2EF
oklch(97.1% 0.015 33.1)
-
Step 100
100
#FEE3DD
oklch(93.6% 0.031 32.6)
-
Step 200
200
#FECCC0
oklch(88.6% 0.059 33.8)
-
Step 300
300
#FDA794
oklch(80.8% 0.106 33.1)
-
Step 400
400
#F87256
oklch(70.7% 0.17 33.3)
-
Step 500
500 (this color)
#EF3F17
oklch(62.8% 0.218 33.4)
-
Step 600
600
#CF2C00
oklch(55.6% 0.203 33.4)
-
Step 700
700
#AF2400
oklch(49.1% 0.179 33.5)
-
Step 800
800
#911C00
oklch(42.7% 0.156 33.4)
-
Step 900
900
#7A1600
oklch(37.7% 0.137 33.5)
-
Step 950
950
#490F04
oklch(27.1% 0.09 33.5)
#EF3F17 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) | #76680B | 0.229 |
| Deuteranopia (no green cones) | #A18F01 | 0.207 |
| Tritanopia (no blue cones) | #FF0039 | 0.059 |
| Achromatopsia (no color) | #818181 | 0.219 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #EF3F17
#EF3F17
oklch(62.8% 0.218 33.4)
- #0099B1
#0099B1
oklch(62.8% 0.11 214)
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 #EF3F17, closest first.
No curated palette has a color within ΔE 0.04 of #EF3F17.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vermillion #F4320C ΔE 0.015
- Tomato Red #EC2D01 ΔE 0.023
- Orangey Red #FA4224 ΔE 0.024
- Red Orange #FD3C06 ΔE 0.026
- Orangered #FE420F ΔE 0.031
- Orange Red #FF4500 ΔE 0.035
- Blood Orange #FE4B03 ΔE 0.038
- Deep Orange #DC4D01 ΔE 0.040
Use #EF3F17 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.