#638099
Closest named color: Grey Blue (#647D8E). oklch(58.7% 0.051 244.8), rgb(99, 128, 153).
Aa
Black text reads best on this color (5.07:1).
About this color
#638099 is a medium-dark, muted blue. In OKLCH its lightness is 59%, its chroma 0.051 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Grey Blue (#647D8E), ΔE 0.017 away. Black text reads best on it, at 5.07:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | muted (0.051) |
| Temperature | cool |
| Nearest name | Grey Blue (#647D8E) |
| Black text | 5.07:1 |
| White text | 4.13:1 |
Values
| HEX | #638099 |
| RGB | rgb(99, 128, 153) |
| HSL | hsl(208, 21%, 49%) |
| OKLCH | oklch(58.7% 0.051 244.8) |
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 #638099 | 4.13:1 | AA large text | Lc -73.9 | Content text, not long reading |
| Black text on #638099 | 5.07:1 | AA | Lc 35.7 | Non-text elements, placeholder text |
| #638099 text on white | 4.13:1 | AA large text | Lc 68.4 | Content text, not long reading |
| #638099 text on black | 5.07:1 | AA | Lc -33.2 | 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 600.
-
Step 50
50
#F4F6F7
oklch(97.2% 0.003 228.8)
-
Step 100
100
#E6EAEE
oklch(93.5% 0.007 247.9)
-
Step 200
200
#D2DAE1
oklch(88.4% 0.013 244.3)
-
Step 300
300
#B5C3CF
oklch(81% 0.023 243.9)
-
Step 400
400
#8EA4B6
oklch(70.8% 0.036 242.9)
-
Step 500
500
#728DA4
oklch(63.1% 0.046 244.3)
-
Step 600
600 (this color)
#638099
oklch(58.7% 0.051 244.8)
-
Step 700
700
#4A647A
oklch(49.1% 0.047 244.5)
-
Step 800
800
#3D5263
oklch(42.8% 0.038 243.2)
-
Step 900
900
#344451
oklch(37.8% 0.03 243.1)
-
Step 950
950
#1F282F
oklch(27.1% 0.018 241.7)
#638099 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) | #76809A | 0.025 |
| Deuteranopia (no green cones) | #6F7A99 | 0.022 |
| Tritanopia (no blue cones) | #518688 | 0.042 |
| Achromatopsia (no color) | #7D7D7D | 0.051 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #638099
#638099
oklch(58.7% 0.051 244.8)
- #92765D
#92765D
oklch(58.6% 0.051 63.4)
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 #638099, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Grey Blue #647D8E ΔE 0.017
- Slate Gray #708090 ΔE 0.021
- Steel #738595 ΔE 0.028
- Stormy Blue #507B9C ΔE 0.029
- Steel Grey #6F828A ΔE 0.029
- Battleship Grey #6B7C85 ΔE 0.030
- Dusty Blue #5A86AD ΔE 0.031
- Off Blue #5684AE ΔE 0.033
Use #638099 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.