#638CA5
Closest named color: Blue Grey (#758DA3). oklch(61.9% 0.059 235.8), rgb(99, 140, 165).
Aa
Black text reads best on this color (5.82:1).
About this color
#638CA5 is a medium-dark, muted blue. In OKLCH its lightness is 62%, its chroma 0.059 and its hue 236°. 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 5.82:1.
| Hue family | Blues |
| Lightness | medium-dark (62%) |
| Chroma | muted (0.059) |
| Temperature | cool |
| Nearest name | Blue Grey (#758DA3) |
| Black text | 5.82:1 |
| White text | 3.60:1 |
Values
| HEX | #638CA5 |
| RGB | rgb(99, 140, 165) |
| HSL | hsl(203, 27%, 52%) |
| OKLCH | oklch(61.9% 0.059 235.8) |
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 #638CA5 | 3.60:1 | AA large text | Lc -69.1 | Content text, not long reading |
| Black text on #638CA5 | 5.82:1 | AA | Lc 40.5 | Non-text elements, placeholder text |
| #638CA5 text on white | 3.60:1 | AA large text | Lc 63.6 | Content text, not long reading |
| #638CA5 text on black | 5.82:1 | AA | Lc -38.1 | 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
#E5EBEF
oklch(93.7% 0.008 236.6)
-
Step 200
200
#D0DBE2
oklch(88.5% 0.015 235.4)
-
Step 300
300
#B0C4D1
oklch(80.9% 0.029 236.3)
-
Step 400
400
#85A6BA
oklch(70.7% 0.047 234.9)
-
Step 500
500 (this color)
#638CA5
oklch(61.9% 0.059 235.8)
-
Step 600
600
#4D7994
oklch(55.5% 0.064 236.5)
-
Step 700
700
#3E667E
oklch(49.1% 0.059 236.1)
-
Step 800
800
#335366
oklch(42.6% 0.049 235.7)
-
Step 900
900
#2D4553
oklch(37.7% 0.038 234.8)
-
Step 950
950
#1B2831
oklch(26.9% 0.025 239.1)
#638CA5 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) | #818BA6 | 0.038 |
| Deuteranopia (no green cones) | #7784A5 | 0.032 |
| Tritanopia (no blue cones) | #4A9394 | 0.046 |
| Achromatopsia (no color) | #878787 | 0.059 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #638CA5
#638CA5
oklch(61.9% 0.059 235.8)
- #A27D64
#A27D64
oklch(61.9% 0.059 55.4)
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 #638CA5, 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 0.026
- Dusty Blue #5A86AD ΔE 0.027
- Light Slate Gray #778899 ΔE 0.028
- Steel #738595 ΔE 0.030
- Off Blue #5684AE ΔE 0.035
- Faded Blue #658CBB ΔE 0.035
- Slate Gray #708090 ΔE 0.040
Use #638CA5 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.