#637AEF
Closest named color: Cornflower (#6A79F7). oklch(62.1% 0.176 272), rgb(99, 122, 239).
Aa
Black text reads best on this color (5.56:1).
About this color
#637AEF is a medium-light, vivid blue. In OKLCH its lightness is 62%, its chroma 0.176 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Cornflower (#6A79F7), ΔE 0.015 away. Black text reads best on it, at 5.56:1.
| Hue family | Blues |
| Lightness | medium-light (62%) |
| Chroma | vivid (0.176) |
| Temperature | cool |
| Nearest name | Cornflower (#6A79F7) |
| Black text | 5.56:1 |
| White text | 3.77:1 |
Values
| HEX | #637AEF |
| RGB | rgb(99, 122, 239) |
| HSL | hsl(230, 81%, 66%) |
| OKLCH | oklch(62.1% 0.176 272) |
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 #637AEF | 3.77:1 | AA large text | Lc -70.5 | Content text, not long reading |
| Black text on #637AEF | 5.56:1 | AA | Lc 39.1 | Non-text elements, placeholder text |
| #637AEF text on white | 3.77:1 | AA large text | Lc 65.0 | Content text, not long reading |
| #637AEF text on black | 5.56:1 | AA | Lc -36.6 | 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E4E9FB
oklch(93.6% 0.025 273.5)
-
Step 200
200
#CED8FA
oklch(88.5% 0.048 272.4)
-
Step 300
300
#ADBEF9
oklch(81% 0.086 271.9)
-
Step 400
400
#839AF6
oklch(70.8% 0.137 271.9)
-
Step 500
500 (this color)
#637AEF
oklch(62.1% 0.176 272)
-
Step 600
600
#4F63E1
oklch(55.6% 0.192 271.8)
-
Step 700
700
#4151C4
oklch(49.1% 0.179 272)
-
Step 800
800
#35439E
oklch(42.6% 0.148 272)
-
Step 900
900
#2D3A7E
oklch(37.7% 0.116 271.6)
-
Step 950
950
#1A224A
oklch(26.9% 0.075 272)
#637AEF 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) | #3D8AF3 | 0.049 |
| Deuteranopia (no green cones) | #237DED | 0.054 |
| Tritanopia (no blue cones) | #0095A9 | 0.155 |
| Achromatopsia (no color) | #838383 | 0.177 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #637AEF
#637AEF
oklch(62.1% 0.176 272)
- #A28300
#A28300
oklch(62.1% 0.127 92.1)
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 #637AEF, closest first.
No curated palette has a color within ΔE 0.04 of #637AEF.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cornflower #6A79F7 ΔE 0.015
- Soft Blue #6488EA ΔE 0.038
- Medium Slate Blue #7B68EE ΔE 0.050
- Clear Blue #247AFD ΔE 0.057
- Dark Sky Blue #448EE4 ΔE 0.061
- Royal Blue #4169E1 ΔE 0.064
- Periwinkle #8E82FE ΔE 0.067
- Lavender Blue #8B88F8 ΔE 0.068
Use #637AEF 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.