#3988BC
Closest named color: Cool Blue (#4984B8). oklch(60.1% 0.11 241), rgb(57, 136, 188).
Aa
Black text reads best on this color (5.42:1).
About this color
#3988BC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.110 and its hue 241°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.015 away. Black text reads best on it, at 5.42:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.110) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.42:1 |
| White text | 3.87:1 |
Values
| HEX | #3988BC |
| RGB | rgb(57, 136, 188) |
| HSL | hsl(204, 53%, 48%) |
| OKLCH | oklch(60.1% 0.11 241) |
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 #3988BC | 3.87:1 | AA large text | Lc -71.4 | Content text, not long reading |
| Black text on #3988BC | 5.42:1 | AA | Lc 38.2 | Non-text elements, placeholder text |
| #3988BC text on white | 3.87:1 | AA large text | Lc 65.9 | Content text, not long reading |
| #3988BC text on black | 5.42:1 | AA | Lc -35.8 | 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
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E1EBF4
oklch(93.5% 0.016 245.1)
-
Step 200
200
#C8DCEB
oklch(88.4% 0.03 240.2)
-
Step 300
300
#A2C6E1
oklch(80.9% 0.054 240.8)
-
Step 400
400
#6EA8D2
oklch(70.8% 0.086 241)
-
Step 500
500 (this color)
#3988BC
oklch(60.1% 0.11 241)
-
Step 600
600
#1B7BB2
oklch(55.7% 0.119 240.4)
-
Step 700
700
#096799
oklch(49.1% 0.111 240.8)
-
Step 800
800
#0F547C
oklch(42.6% 0.092 240.8)
-
Step 900
900
#174664
oklch(37.8% 0.072 240.7)
-
Step 950
950
#0F293B
oklch(27% 0.046 241.6)
#3988BC 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) | #7088BE | 0.056 |
| Deuteranopia (no green cones) | #5E7CBB | 0.045 |
| Tritanopia (no blue cones) | #00959A | 0.077 |
| Achromatopsia (no color) | #818181 | 0.110 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3988BC
#3988BC
oklch(60.1% 0.11 241)
- #B07034
#B07034
oklch(60.2% 0.11 61.1)
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 #3988BC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.015
- Steel Blue #4682B4 ΔE 0.019
- Blue NCS #118AB2 ΔE 0.027
- Off Blue #5684AE ΔE 0.030
- Water Blue #0E87CC ΔE 0.031
- Dusty Blue #5A86AD ΔE 0.035
- Faded Blue #658CBB ΔE 0.045
- Windows Blue #3778BF ΔE 0.047
Use #3988BC 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.