#1C66E4
Closest named color: Cerulean Blue (#056EEE). oklch(54.4% 0.204 260.7), rgb(28, 102, 228).
Aa
White text reads best on this color (5.15:1).
About this color
#1C66E4 is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.204 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean Blue (#056EEE), ΔE 0.024 away. White text reads best on it, at 5.15:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.204) |
| Temperature | cool |
| Nearest name | Cerulean Blue (#056EEE) |
| Black text | 4.07:1 |
| White text | 5.15:1 |
Values
| HEX | #1C66E4 |
| RGB | rgb(28, 102, 228) |
| HSL | hsl(218, 79%, 50%) |
| OKLCH | oklch(54.4% 0.204 260.7) |
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 #1C66E4 | 5.15:1 | AA | Lc -80.2 | Fine for body text |
| Black text on #1C66E4 | 4.07:1 | AA large text | Lc 29.3 | Dividers and decoration only |
| #1C66E4 text on white | 5.15:1 | AA | Lc 74.8 | Content text, not long reading |
| #1C66E4 text on black | 4.07:1 | AA large text | Lc -26.9 | Dividers and decoration only |
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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E0EBFC
oklch(93.7% 0.026 259)
-
Step 200
200
#C6DAFC
oklch(88.4% 0.052 261.1)
-
Step 300
300
#9FC2FD
oklch(81% 0.092 260.7)
-
Step 400
400
#6A9FFB
oklch(70.6% 0.147 260.8)
-
Step 500
500
#4184F9
oklch(63.1% 0.188 260.7)
-
Step 600
600 (this color)
#1C66E4
oklch(54.4% 0.204 260.7)
-
Step 700
700
#1357CA
oklch(49.1% 0.19 260.8)
-
Step 800
800
#1348A3
oklch(42.7% 0.157 260.7)
-
Step 900
900
#173E81
oklch(37.8% 0.122 260.5)
-
Step 950
950
#0E254C
oklch(27.1% 0.078 260.3)
#1C66E4 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) | #0076E8 | 0.039 |
| Deuteranopia (no green cones) | #0065E2 | 0.010 |
| Tritanopia (no blue cones) | #00869B | 0.157 |
| Achromatopsia (no color) | #6D6D6D | 0.205 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1C66E4
#1C66E4
oklch(54.4% 0.204 260.7)
- #916700
#916700
oklch(54.3% 0.112 80.5)
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 #1C66E4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean Blue #056EEE ΔE 0.024
- Azul #1D5DEC ΔE 0.024
- Royal Blue #4169E1 ΔE 0.030
- Neon Blue #4361EE ΔE 0.034
- Bright Blue #0165FC ΔE 0.037
- Warm Blue #4B57DB ΔE 0.048
- Electric Blue #0652FF ΔE 0.061
- Clear Blue #247AFD ΔE 0.062
Use #1C66E4 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.