#0137C9
Closest named color: Blue Blue (#2242C7). oklch(42.9% 0.228 263.6), rgb(1, 55, 201).
Aa
White text reads best on this color (8.78:1).
About this color
#0137C9 is a dark, vivid blue. In OKLCH its lightness is 43%, its chroma 0.228 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Blue Blue (#2242C7), ΔE 0.032 away. White text reads best on it, at 8.78:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | vivid (0.228) |
| Temperature | cool |
| Nearest name | Blue Blue (#2242C7) |
| Black text | 2.39:1 |
| White text | 8.78:1 |
Values
| HEX | #0137C9 |
| RGB | rgb(1, 55, 201) |
| HSL | hsl(224, 99%, 40%) |
| OKLCH | oklch(42.9% 0.228 263.6) |
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 #0137C9 | 8.78:1 | AAA | Lc -93.2 | Preferred for body text |
| Black text on #0137C9 | 2.39:1 | Fails | Lc 15.4 | Dividers and decoration only |
| #0137C9 text on white | 8.78:1 | AAA | Lc 88.6 | Fine for body text |
| #0137C9 text on black | 2.39:1 | Fails | Lc -13.6 | Not readable |
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 800.
-
Step 50
50
#F1F6FF
oklch(97.2% 0.013 262.4)
-
Step 100
100
#DFEAFF
oklch(93.5% 0.031 263.5)
-
Step 200
200
#C6DAFF
oklch(88.5% 0.056 262.8)
-
Step 300
300
#A1C1FF
oklch(81% 0.095 263.3)
-
Step 400
400
#6E9DFF
oklch(70.6% 0.153 263.6)
-
Step 500
500
#4881FF
oklch(63.2% 0.197 263.5)
-
Step 600
600
#1F60FF
oklch(55.6% 0.244 263.5)
-
Step 700
700
#0043F2
oklch(49.1% 0.263 263.5)
-
Step 800
800 (this color)
#0137C9
oklch(42.9% 0.228 263.6)
-
Step 900
900
#09339D
oklch(37.7% 0.177 263.6)
-
Step 950
950
#07205C
oklch(27.1% 0.112 263.4)
#0137C9 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) | #0054CD | 0.064 |
| Deuteranopia (no green cones) | #0041C6 | 0.020 |
| Tritanopia (no blue cones) | #00627D | 0.172 |
| Achromatopsia (no color) | #4B4B4B | 0.228 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #0137C9
#0137C9
oklch(42.9% 0.228 263.6)
- #664A00
#664A00
oklch(42.8% 0.088 83.6)
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 #0137C9, closest first.
No curated palette has a color within ΔE 0.04 of #0137C9.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue Blue #2242C7 ΔE 0.032
- Sapphire #2138AB ΔE 0.051
- True Blue #010FCC ΔE 0.051
- Ultramarine Blue #1805DB ΔE 0.052
- Majorelle Blue #3F37C9 ΔE 0.054
- Pure Blue #0203E2 ΔE 0.059
- Medium Blue #0000CD ΔE 0.059
- Vibrant Blue #0339F8 ΔE 0.075
Use #0137C9 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.