#137BBB
Closest named color: Nice Blue (#107AB0). oklch(56.1% 0.131 243.5), rgb(19, 123, 187).
Aa
White text reads best on this color (4.58:1).
About this color
#137BBB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.131 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Nice Blue (#107AB0), ΔE 0.017 away. White text reads best on it, at 4.58:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.131) |
| Temperature | cool |
| Nearest name | Nice Blue (#107AB0) |
| Black text | 4.57:1 |
| White text | 4.58:1 |
Values
| HEX | #137BBB |
| RGB | rgb(19, 123, 187) |
| HSL | hsl(203, 82%, 40%) |
| OKLCH | oklch(56.1% 0.131 243.5) |
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 #137BBB | 4.58:1 | AA | Lc -76.8 | Fine for body text |
| Black text on #137BBB | 4.57:1 | AA | Lc 32.7 | Non-text elements, placeholder text |
| #137BBB text on white | 4.58:1 | AA | Lc 71.3 | Content text, not long reading |
| #137BBB text on black | 4.57:1 | AA | Lc -30.3 | 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
#C7DCEE
oklch(88.4% 0.034 244)
-
Step 300
300
#A1C6E4
oklch(81% 0.058 243)
-
Step 400
400
#6BA7D7
oklch(70.6% 0.094 243.8)
-
Step 500
500
#3E90CC
oklch(63% 0.12 243.7)
-
Step 600
600 (this color)
#137BBB
oklch(56.1% 0.131 243.5)
-
Step 700
700
#00669F
oklch(49.1% 0.12 243.6)
-
Step 800
800
#075382
oklch(42.6% 0.102 244.1)
-
Step 900
900
#144568
oklch(37.6% 0.079 244.1)
-
Step 950
950
#0E293D
oklch(27.1% 0.05 243.6)
#137BBB 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) | #5C7DBE | 0.057 |
| Deuteranopia (no green cones) | #456FBA | 0.042 |
| Tritanopia (no blue cones) | #008B92 | 0.090 |
| Achromatopsia (no color) | #757575 | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #137BBB
#137BBB
oklch(56.1% 0.131 243.5)
- #A76100
#A76100
oklch(56% 0.127 63.5)
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 #137BBB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Nice Blue #107AB0 ΔE 0.017
- Windows Blue #3778BF ΔE 0.021
- Flat Blue #3C73A8 ΔE 0.037
- Water Blue #0E87CC ΔE 0.039
- Steel Blue #4682B4 ΔE 0.042
- Mid Blue #276AB3 ΔE 0.047
- Cool Blue #4984B8 ΔE 0.047
- Muted Blue #3B719F ΔE 0.048
Use #137BBB 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.