#1C66DD
Closest named color: Royal Blue (#4169E1). oklch(53.9% 0.196 260.1), rgb(28, 102, 221).
Aa
White text reads best on this color (5.25:1).
About this color
#1C66DD is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.196 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.031 away. White text reads best on it, at 5.25:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.196) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 3.99:1 |
| White text | 5.25:1 |
Values
| HEX | #1C66DD |
| RGB | rgb(28, 102, 221) |
| HSL | hsl(217, 78%, 49%) |
| OKLCH | oklch(53.9% 0.196 260.1) |
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 #1C66DD | 5.25:1 | AA | Lc -80.8 | Fine for body text |
| Black text on #1C66DD | 3.99:1 | AA large text | Lc 28.7 | Dividers and decoration only |
| #1C66DD text on white | 5.25:1 | AA | Lc 75.4 | Fine for body text |
| #1C66DD text on black | 3.99:1 | AA large text | Lc -26.3 | 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
#E0EBFB
oklch(93.7% 0.025 257.6)
-
Step 200
200
#C7DAFA
oklch(88.4% 0.049 260.9)
-
Step 300
300
#A0C2FA
oklch(80.9% 0.088 260.2)
-
Step 400
400
#6BA0F8
oklch(70.7% 0.141 260.1)
-
Step 500
500
#4385F4
oklch(63.1% 0.18 260.2)
-
Step 600
600 (this color)
#1C66DD
oklch(53.9% 0.196 260.1)
-
Step 700
700
#1559C5
oklch(49.1% 0.181 260.1)
-
Step 800
800
#14499F
oklch(42.6% 0.15 260.1)
-
Step 900
900
#183E7F
oklch(37.6% 0.118 260.4)
-
Step 950
950
#0F254A
oklch(27% 0.074 260.2)
#1C66DD 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) | #0075E1 | 0.037 |
| Deuteranopia (no green cones) | #0064DB | 0.012 |
| Tritanopia (no blue cones) | #008497 | 0.151 |
| Achromatopsia (no color) | #6C6C6C | 0.196 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1C66DD
#1C66DD
oklch(53.9% 0.196 260.1)
- #906600
#906600
oklch(54% 0.112 80.3)
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 #1C66DD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.031
- Cerulean Blue #056EEE ΔE 0.031
- Azul #1D5DEC ΔE 0.032
- Neon Blue #4361EE ΔE 0.041
- Bright Blue #0165FC ΔE 0.047
- Warm Blue #4B57DB ΔE 0.048
- Mid Blue #276AB3 ΔE 0.068
- Electric Blue #0652FF ΔE 0.069
Use #1C66DD 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.