#638FB3
Closest named color: Faded Blue (#658CBB). oklch(63.2% 0.073 244), rgb(99, 143, 179).
Aa
Black text reads best on this color (6.11:1).
About this color
#638FB3 is a medium-light, moderately saturated blue. In OKLCH its lightness is 63%, its chroma 0.073 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Faded Blue (#658CBB), ΔE 0.017 away. Black text reads best on it, at 6.11:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | moderately saturated (0.073) |
| Temperature | cool |
| Nearest name | Faded Blue (#658CBB) |
| Black text | 6.11:1 |
| White text | 3.43:1 |
Values
| HEX | #638FB3 |
| RGB | rgb(99, 143, 179) |
| HSL | hsl(207, 34%, 55%) |
| OKLCH | oklch(63.2% 0.073 244) |
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 #638FB3 | 3.43:1 | AA large text | Lc -67.3 | Content text, not long reading |
| Black text on #638FB3 | 6.11:1 | AA | Lc 42.3 | Non-text elements, placeholder text |
| #638FB3 text on white | 3.43:1 | AA large text | Lc 61.8 | Content text, not long reading |
| #638FB3 text on black | 6.11:1 | AA | Lc -39.9 | 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
#E4EBF0
oklch(93.6% 0.01 238.5)
-
Step 200
200
#CFDBE6
oklch(88.6% 0.02 245.7)
-
Step 300
300
#AEC4D6
oklch(80.9% 0.035 242.8)
-
Step 400
400
#83A5C2
oklch(70.7% 0.057 244.5)
-
Step 500
500 (this color)
#638FB3
oklch(63.2% 0.073 244)
-
Step 600
600
#49789E
oklch(55.5% 0.079 244.3)
-
Step 700
700
#3A6587
oklch(49.1% 0.073 243.9)
-
Step 800
800
#30536E
oklch(42.8% 0.061 243.1)
-
Step 900
900
#2B4459
oklch(37.6% 0.048 244.9)
-
Step 950
950
#1A2834
oklch(27% 0.03 245.1)
#638FB3 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) | #808FB5 | 0.036 |
| Deuteranopia (no green cones) | #7587B2 | 0.029 |
| Tritanopia (no blue cones) | #42989B | 0.061 |
| Achromatopsia (no color) | #8A8A8A | 0.073 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #638FB3
#638FB3
oklch(63.2% 0.073 244)
- #A9815B
#A9815B
oklch(63.3% 0.072 64.5)
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 #638FB3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Faded Blue #658CBB ΔE 0.017
- Silver Lake Blue #778DA9 ΔE 0.026
- Dusty Blue #5A86AD ΔE 0.029
- Blue Grey #758DA3 ΔE 0.030
- Off Blue #5684AE ΔE 0.036
- Light Slate Gray #778899 ΔE 0.042
- Cool Blue #4984B8 ΔE 0.046
- Steel #738595 ΔE 0.047
Use #638FB3 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.