#4273DE
Closest named color: Royal Blue (#4169E1). oklch(57.8% 0.172 263.5), rgb(66, 115, 222).
Aa
Black text reads best on this color (4.73:1).
About this color
#4273DE is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.172 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.026 away. Black text reads best on it, at 4.73:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.172) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.73:1 |
| White text | 4.43:1 |
Values
| HEX | #4273DE |
| RGB | rgb(66, 115, 222) |
| HSL | hsl(221, 70%, 56%) |
| OKLCH | oklch(57.8% 0.172 263.5) |
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 #4273DE | 4.43:1 | AA large text | Lc -75.8 | Fine for body text |
| Black text on #4273DE | 4.73:1 | AA | Lc 33.7 | Non-text elements, placeholder text |
| #4273DE text on white | 4.43:1 | AA large text | Lc 70.4 | Content text, not long reading |
| #4273DE text on black | 4.73:1 | AA | Lc -31.3 | 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
#F2F6FD
oklch(97.2% 0.01 261.8)
-
Step 100
100
#E2EAF9
oklch(93.5% 0.022 263.2)
-
Step 200
200
#CBDAF6
oklch(88.6% 0.042 263)
-
Step 300
300
#A7C1F3
oklch(80.9% 0.077 263.3)
-
Step 400
400
#789FEE
oklch(70.7% 0.124 263.5)
-
Step 500
500
#5685E8
oklch(63.1% 0.158 263.4)
-
Step 600
600 (this color)
#4273DE
oklch(57.8% 0.172 263.5)
-
Step 700
700
#2E5ABA
oklch(49.2% 0.16 263.2)
-
Step 800
800
#274A96
oklch(42.7% 0.131 263.3)
-
Step 900
900
#243E78
oklch(37.6% 0.104 263.9)
-
Step 950
950
#152546
oklch(27% 0.065 263.2)
#4273DE 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) | #387FE2 | 0.030 |
| Deuteranopia (no green cones) | #0371DC | 0.035 |
| Tritanopia (no blue cones) | #008C9E | 0.137 |
| Achromatopsia (no color) | #787878 | 0.172 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4273DE
#4273DE
oklch(57.8% 0.172 263.5)
- #9B7200
#9B7200
oklch(57.8% 0.119 83.4)
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 #4273DE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.026
- Cerulean Blue #056EEE ΔE 0.044
- Clear Blue #247AFD ΔE 0.050
- Neon Blue #4361EE ΔE 0.051
- Windows Blue #3778BF ΔE 0.053
- Dark Periwinkle #665FD1 ΔE 0.061
- Cornflower #6A79F7 ΔE 0.063
- Warm Blue #4B57DB ΔE 0.067
Use #4273DE 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.