#637ECF
Closest named color: Soft Blue (#6488EA). oklch(60.9% 0.127 268.5), rgb(99, 126, 207).
Aa
Black text reads best on this color (5.41:1).
About this color
#637ECF is a medium-dark, moderately saturated blue. In OKLCH its lightness is 61%, its chroma 0.127 and its hue 269°. Its hue sits on the cool side of the wheel. The nearest named color is Soft Blue (#6488EA), ΔE 0.045 away. Black text reads best on it, at 5.41:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | Soft Blue (#6488EA) |
| Black text | 5.41:1 |
| White text | 3.87:1 |
Values
| HEX | #637ECF |
| RGB | rgb(99, 126, 207) |
| HSL | hsl(225, 53%, 60%) |
| OKLCH | oklch(60.9% 0.127 268.5) |
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 #637ECF | 3.87:1 | AA large text | Lc -71.6 | Content text, not long reading |
| Black text on #637ECF | 5.41:1 | AA | Lc 38.0 | Non-text elements, placeholder text |
| #637ECF text on white | 3.87:1 | AA large text | Lc 66.1 | Content text, not long reading |
| #637ECF text on black | 5.41:1 | AA | Lc -35.6 | 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
#F3F5FB
oklch(97% 0.008 271.3)
-
Step 100
100
#E5EAF6
oklch(93.7% 0.017 267.8)
-
Step 200
200
#CFD9F1
oklch(88.5% 0.035 267.6)
-
Step 300
300
#B0C0EA
oklch(81% 0.062 268.6)
-
Step 400
400
#869EDF
oklch(70.6% 0.099 268.3)
-
Step 500
500 (this color)
#637ECF
oklch(60.9% 0.127 268.5)
-
Step 600
600
#526DC4
oklch(55.7% 0.138 268.6)
-
Step 700
700
#425AA9
oklch(49% 0.129 268.6)
-
Step 800
800
#374A89
oklch(42.7% 0.107 268.9)
-
Step 900
900
#2F3F6D
oklch(37.8% 0.082 267.9)
-
Step 950
950
#1C2540
oklch(27.1% 0.052 268.8)
#637ECF 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) | #5E86D2 | 0.021 |
| Deuteranopia (no green cones) | #517DCD | 0.021 |
| Tritanopia (no blue cones) | #308F9C | 0.114 |
| Achromatopsia (no color) | #818181 | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #637ECF
#637ECF
oklch(60.9% 0.127 268.5)
- #A17E00
#A17E00
oklch(61% 0.125 89.1)
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 #637ECF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Soft Blue #6488EA ΔE 0.045
- Cool Blue #4984B8 ΔE 0.051
- Dark Sky Blue #448EE4 ΔE 0.052
- Faded Blue #658CBB ΔE 0.055
- Windows Blue #3778BF ΔE 0.056
- Steel Blue #4682B4 ΔE 0.056
- Off Blue #5684AE ΔE 0.060
- Water Blue #0E87CC ΔE 0.062
Use #637ECF 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.