#3988CB
Closest named color: Water Blue (#0E87CC). oklch(60.9% 0.128 247.5), rgb(57, 136, 203).
Aa
Black text reads best on this color (5.55:1).
About this color
#3988CB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 61%, its chroma 0.128 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.020 away. Black text reads best on it, at 5.55:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.55:1 |
| White text | 3.77:1 |
Values
| HEX | #3988CB |
| RGB | rgb(57, 136, 203) |
| HSL | hsl(208, 58%, 51%) |
| OKLCH | oklch(60.9% 0.128 247.5) |
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 #3988CB | 3.77:1 | AA large text | Lc -70.5 | Content text, not long reading |
| Black text on #3988CB | 5.55:1 | AA | Lc 39.1 | Non-text elements, placeholder text |
| #3988CB text on white | 3.77:1 | AA large text | Lc 65.0 | Content text, not long reading |
| #3988CB text on black | 5.55:1 | AA | Lc -36.7 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF6
oklch(93.6% 0.018 250.6)
-
Step 200
200
#C8DCEF
oklch(88.5% 0.034 246.8)
-
Step 300
300
#A1C5E8
oklch(80.9% 0.063 247.9)
-
Step 400
400
#6CA6DC
oklch(70.7% 0.1 247.7)
-
Step 500
500 (this color)
#3988CB
oklch(60.9% 0.128 247.5)
-
Step 600
600
#1778BF
oklch(55.7% 0.138 247.1)
-
Step 700
700
#0464A5
oklch(49% 0.129 247.6)
-
Step 800
800
#0C5286
oklch(42.7% 0.107 247.5)
-
Step 900
900
#15446B
oklch(37.6% 0.084 247.6)
-
Step 950
950
#0E283F
oklch(26.9% 0.054 248)
#3988CB 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) | #6A8BCE | 0.050 |
| Deuteranopia (no green cones) | #557DCA | 0.036 |
| Tritanopia (no blue cones) | #0098A0 | 0.094 |
| Achromatopsia (no color) | #838383 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3988CB
#3988CB
oklch(60.9% 0.128 247.5)
- #B57215
#B57215
oklch(61% 0.128 67.6)
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 #3988CB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.020
- Cool Blue #4984B8 ΔE 0.030
- Steel Blue #4682B4 ΔE 0.036
- Dark Sky Blue #448EE4 ΔE 0.041
- Windows Blue #3778BF ΔE 0.046
- Blue NCS #118AB2 ΔE 0.047
- Off Blue #5684AE ΔE 0.047
- Faded Blue #658CBB ΔE 0.050
Use #3988CB 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.