#0173EB
Closest named color: Cerulean Blue (#056EEE). oklch(57.3% 0.201 256.7), rgb(1, 115, 235).
Aa
Black text reads best on this color (4.65:1).
About this color
#0173EB is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.201 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean Blue (#056EEE), ΔE 0.013 away. Black text reads best on it, at 4.65:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.201) |
| Temperature | cool |
| Nearest name | Cerulean Blue (#056EEE) |
| Black text | 4.65:1 |
| White text | 4.51:1 |
Values
| HEX | #0173EB |
| RGB | rgb(1, 115, 235) |
| HSL | hsl(211, 99%, 46%) |
| OKLCH | oklch(57.3% 0.201 256.7) |
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 #0173EB | 4.51:1 | AA | Lc -75.9 | Fine for body text |
| Black text on #0173EB | 4.65:1 | AA | Lc 33.6 | Non-text elements, placeholder text |
| #0173EB text on white | 4.51:1 | AA | Lc 70.5 | Content text, not long reading |
| #0173EB text on black | 4.65:1 | AA | Lc -31.2 | 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
#F0F6FE
oklch(97.1% 0.012 255.5)
-
Step 100
100
#DFEBFC
oklch(93.6% 0.026 257)
-
Step 200
200
#C4DBFB
oklch(88.5% 0.051 256.7)
-
Step 300
300
#9BC3FB
oklch(80.9% 0.091 256.9)
-
Step 400
400
#62A2F9
oklch(70.8% 0.144 256.5)
-
Step 500
500
#3287F6
oklch(63.1% 0.185 256.8)
-
Step 600
600 (this color)
#0173EB
oklch(57.3% 0.201 256.7)
-
Step 700
700
#005CBF
oklch(49% 0.172 256.8)
-
Step 800
800
#004B9E
oklch(42.6% 0.15 256.7)
-
Step 900
900
#0B3F80
oklch(37.6% 0.122 257)
-
Step 950
950
#0A264B
oklch(27.1% 0.076 256.8)
#0173EB 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) | #1A80EF | 0.036 |
| Deuteranopia (no green cones) | #006EE9 | 0.013 |
| Tritanopia (no blue cones) | #0091A4 | 0.151 |
| Achromatopsia (no color) | #767676 | 0.201 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #0173EB
#0173EB
oklch(57.3% 0.201 256.7)
- #A06D00
#A06D00
oklch(57.4% 0.12 76.5)
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 #0173EB, closest first.
No curated palette has a color within ΔE 0.04 of #0173EB.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean Blue #056EEE ΔE 0.013
- Clear Blue #247AFD ΔE 0.035
- Royal Blue #4169E1 ΔE 0.038
- Bright Blue #0165FC ΔE 0.043
- Neon Blue #4361EE ΔE 0.049
- Azul #1D5DEC ΔE 0.052
- Windows Blue #3778BF ΔE 0.074
- Warm Blue #4B57DB ΔE 0.074
Use #0173EB 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.