#638FAC
Closest named color: Blue Grey (#758DA3). oklch(62.9% 0.065 238), rgb(99, 143, 172).
Aa
Black text reads best on this color (6.05:1).
About this color
#638FAC is a medium-light, muted blue. In OKLCH its lightness is 63%, its chroma 0.065 and its hue 238°. Its hue sits on the cool side of the wheel. The nearest named color is Blue Grey (#758DA3), ΔE 0.023 away. Black text reads best on it, at 6.05:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | muted (0.065) |
| Temperature | cool |
| Nearest name | Blue Grey (#758DA3) |
| Black text | 6.05:1 |
| White text | 3.46:1 |
Values
| HEX | #638FAC |
| RGB | rgb(99, 143, 172) |
| HSL | hsl(204, 31%, 53%) |
| OKLCH | oklch(62.9% 0.065 238) |
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 #638FAC | 3.46:1 | AA large text | Lc -67.6 | Content text, not long reading |
| Black text on #638FAC | 6.05:1 | AA | Lc 41.9 | Non-text elements, placeholder text |
| #638FAC text on white | 3.46:1 | AA large text | Lc 62.2 | Content text, not long reading |
| #638FAC text on black | 6.05:1 | AA | Lc -39.5 | 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
#F3F6F8
oklch(97.1% 0.004 236.5)
-
Step 100
100
#E4EBEF
oklch(93.6% 0.009 232.4)
-
Step 200
200
#CFDBE4
oklch(88.5% 0.018 240)
-
Step 300
300
#AEC4D3
oklch(80.8% 0.032 237.7)
-
Step 400
400
#83A6BD
oklch(70.7% 0.051 237.2)
-
Step 500
500 (this color)
#638FAC
oklch(62.9% 0.065 238)
-
Step 600
600
#4A7998
oklch(55.5% 0.071 238.7)
-
Step 700
700
#3B6682
oklch(49.1% 0.066 238.6)
-
Step 800
800
#315369
oklch(42.6% 0.054 238.2)
-
Step 900
900
#2B4556
oklch(37.7% 0.043 238.1)
-
Step 950
950
#1A2832
oklch(26.9% 0.027 240.1)
#638FAC 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) | #828EAD | 0.039 |
| Deuteranopia (no green cones) | #7886AC | 0.034 |
| Tritanopia (no blue cones) | #469698 | 0.051 |
| Achromatopsia (no color) | #8A8A8A | 0.065 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #638FAC
#638FAC
oklch(62.9% 0.065 238)
- #A77F62
#A77F62
oklch(62.8% 0.065 57.2)
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 #638FAC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue Grey #758DA3 ΔE 0.023
- Silver Lake Blue #778DA9 ΔE 0.024
- Faded Blue #658CBB ΔE 0.027
- Dusty Blue #5A86AD ΔE 0.030
- Light Slate Gray #778899 ΔE 0.035
- Off Blue #5684AE ΔE 0.038
- Steel #738595 ΔE 0.040
- Cool Blue #4984B8 ΔE 0.051
Use #638FAC 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.