#637FCD
Closest named color: Soft Blue (#6488EA). oklch(61% 0.123 267.7), rgb(99, 127, 205).
Aa
Black text reads best on this color (5.44:1).
About this color
#637FCD is a medium-dark, moderately saturated blue. In OKLCH its lightness is 61%, its chroma 0.123 and its hue 268°. Its hue sits on the cool side of the wheel. The nearest named color is Soft Blue (#6488EA), ΔE 0.046 away. Black text reads best on it, at 5.44:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | moderately saturated (0.123) |
| Temperature | cool |
| Nearest name | Soft Blue (#6488EA) |
| Black text | 5.44:1 |
| White text | 3.85:1 |
Values
| HEX | #637FCD |
| RGB | rgb(99, 127, 205) |
| HSL | hsl(224, 51%, 60%) |
| OKLCH | oklch(61% 0.123 267.7) |
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 #637FCD | 3.85:1 | AA large text | Lc -71.4 | Content text, not long reading |
| Black text on #637FCD | 5.44:1 | AA | Lc 38.2 | Non-text elements, placeholder text |
| #637FCD text on white | 3.85:1 | AA large text | Lc 65.9 | Content text, not long reading |
| #637FCD text on black | 5.44:1 | AA | Lc -35.8 | 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
#F3F5FB
oklch(97% 0.008 271.3)
-
Step 100
100
#E5EAF6
oklch(93.7% 0.017 267.8)
-
Step 200
200
#CFD9F0
oklch(88.5% 0.033 266.9)
-
Step 300
300
#B0C0E9
oklch(80.9% 0.061 268.3)
-
Step 400
400
#869FDD
oklch(70.8% 0.096 267.1)
-
Step 500
500 (this color)
#637FCD
oklch(61% 0.123 267.7)
-
Step 600
600
#516EC1
oklch(55.6% 0.133 267.5)
-
Step 700
700
#425BA7
oklch(49.1% 0.125 267.9)
-
Step 800
800
#364B87
oklch(42.7% 0.103 267.4)
-
Step 900
900
#2F3F6C
oklch(37.7% 0.08 267.7)
-
Step 950
950
#1C253F
oklch(27% 0.05 268.4)
#637FCD 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) | #6087D0 | 0.021 |
| Deuteranopia (no green cones) | #547DCB | 0.019 |
| Tritanopia (no blue cones) | #31909C | 0.111 |
| Achromatopsia (no color) | #828282 | 0.123 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #637FCD
#637FCD
oklch(61% 0.123 267.7)
- #A27E07
#A27E07
oklch(61.1% 0.123 88.2)
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 #637FCD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Soft Blue #6488EA ΔE 0.046
- Cool Blue #4984B8 ΔE 0.048
- Faded Blue #658CBB ΔE 0.051
- Dark Sky Blue #448EE4 ΔE 0.052
- Steel Blue #4682B4 ΔE 0.053
- Windows Blue #3778BF ΔE 0.056
- Off Blue #5684AE ΔE 0.056
- Dusty Blue #5A86AD ΔE 0.059
Use #637FCD 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.