#187DBE
Closest named color: Windows Blue (#3778BF). oklch(56.8% 0.132 244), rgb(24, 125, 190).
Aa
Black text reads best on this color (4.71:1).
About this color
#187DBE is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.132 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.020 away. Black text reads best on it, at 4.71:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.132) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.71:1 |
| White text | 4.45:1 |
Values
| HEX | #187DBE |
| RGB | rgb(24, 125, 190) |
| HSL | hsl(203, 78%, 42%) |
| OKLCH | oklch(56.8% 0.132 244) |
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 #187DBE | 4.45:1 | AA large text | Lc -75.9 | Fine for body text |
| Black text on #187DBE | 4.71:1 | AA | Lc 33.7 | Non-text elements, placeholder text |
| #187DBE text on white | 4.45:1 | AA large text | Lc 70.4 | Content text, not long reading |
| #187DBE text on black | 4.71:1 | AA | Lc -31.3 | 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 600.
-
Step 50
50
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E1EBF5
oklch(93.5% 0.017 248)
-
Step 200
200
#C8DCEE
oklch(88.5% 0.033 245.3)
-
Step 300
300
#A1C6E5
oklch(81% 0.059 243.9)
-
Step 400
400
#6BA7D8
oklch(70.7% 0.095 244.4)
-
Step 500
500
#3E90CD
oklch(63% 0.121 244.1)
-
Step 600
600 (this color)
#187DBE
oklch(56.8% 0.132 244)
-
Step 700
700
#0066A0
oklch(49.2% 0.121 244)
-
Step 800
800
#085382
oklch(42.6% 0.102 244.3)
-
Step 900
900
#144568
oklch(37.6% 0.079 244.1)
-
Step 950
950
#0E293D
oklch(27.1% 0.05 243.6)
#187DBE 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) | #5E7FC1 | 0.057 |
| Deuteranopia (no green cones) | #4771BD | 0.042 |
| Tritanopia (no blue cones) | #008D94 | 0.092 |
| Achromatopsia (no color) | #777777 | 0.132 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #187DBE
#187DBE
oklch(56.8% 0.132 244)
- #AA6300
#AA6300
oklch(56.7% 0.129 63.7)
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 #187DBE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.020
- Nice Blue #107AB0 ΔE 0.023
- Water Blue #0E87CC ΔE 0.032
- Steel Blue #4682B4 ΔE 0.038
- Flat Blue #3C73A8 ΔE 0.041
- Cool Blue #4984B8 ΔE 0.042
- Blue NCS #118AB2 ΔE 0.046
- Mid Blue #276AB3 ΔE 0.053
Use #187DBE 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.