#638FBC
Closest named color: Faded Blue (#658CBB). oklch(63.6% 0.083 249.8), rgb(99, 143, 188).
Aa
Black text reads best on this color (6.18:1).
About this color
#638FBC is a medium-light, moderately saturated blue. In OKLCH its lightness is 64%, its chroma 0.083 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Faded Blue (#658CBB), ΔE 0.008 away. Black text reads best on it, at 6.18:1.
| Hue family | Blues |
| Lightness | medium-light (64%) |
| Chroma | moderately saturated (0.083) |
| Temperature | cool |
| Nearest name | Faded Blue (#658CBB) |
| Black text | 6.18:1 |
| White text | 3.39:1 |
Values
| HEX | #638FBC |
| RGB | rgb(99, 143, 188) |
| HSL | hsl(210, 40%, 56%) |
| OKLCH | oklch(63.6% 0.083 249.8) |
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 #638FBC | 3.39:1 | AA large text | Lc -66.8 | Content text, not long reading |
| Black text on #638FBC | 6.18:1 | AA | Lc 42.7 | Non-text elements, placeholder text |
| #638FBC text on white | 3.39:1 | AA large text | Lc 61.3 | Content text, not long reading |
| #638FBC text on black | 6.18:1 | AA | Lc -40.3 | 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
#F3F6F9
oklch(97.2% 0.005 247.9)
-
Step 100
100
#E4EBF2
oklch(93.7% 0.012 248)
-
Step 200
200
#CEDBE8
oklch(88.6% 0.023 248.1)
-
Step 300
300
#ADC3DB
oklch(80.8% 0.042 250.6)
-
Step 400
400
#82A4C8
oklch(70.6% 0.065 250.2)
-
Step 500
500 (this color)
#638FBC
oklch(63.6% 0.083 249.8)
-
Step 600
600
#4777A6
oklch(55.6% 0.09 249.3)
-
Step 700
700
#39648F
oklch(49.2% 0.084 249.9)
-
Step 800
800
#2F5274
oklch(42.8% 0.07 249.1)
-
Step 900
900
#2A445D
oklch(37.7% 0.054 248.5)
-
Step 950
950
#192837
oklch(27.1% 0.035 249.2)
#638FBC 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) | #7D90BE | 0.032 |
| Deuteranopia (no green cones) | #7287BB | 0.026 |
| Tritanopia (no blue cones) | #3C999E | 0.072 |
| Achromatopsia (no color) | #8B8B8B | 0.083 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #638FBC
#638FBC
oklch(63.6% 0.083 249.8)
- #AC8251
#AC8251
oklch(63.7% 0.084 69.7)
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 #638FBC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Faded Blue #658CBB ΔE 0.008
- Dusty Blue #5A86AD ΔE 0.033
- Silver Lake Blue #778DA9 ΔE 0.035
- Off Blue #5684AE ΔE 0.039
- Blue Grey #758DA3 ΔE 0.041
- Cool Blue #4984B8 ΔE 0.044
- Steel Blue #4682B4 ΔE 0.051
- Light Slate Gray #778899 ΔE 0.054
Use #638FBC 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.