#4273ED
Closest named color: Royal Blue (#4169E1). oklch(58.9% 0.192 264.7), rgb(66, 115, 237).
Aa
Black text reads best on this color (4.90:1).
About this color
#4273ED is a medium-dark, vivid blue. In OKLCH its lightness is 59%, its chroma 0.192 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.030 away. Black text reads best on it, at 4.90:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | vivid (0.192) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.90:1 |
| White text | 4.27:1 |
Values
| HEX | #4273ED |
| RGB | rgb(66, 115, 237) |
| HSL | hsl(223, 83%, 59%) |
| OKLCH | oklch(58.9% 0.192 264.7) |
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 #4273ED | 4.27:1 | AA large text | Lc -74.6 | Content text, not long reading |
| Black text on #4273ED | 4.90:1 | AA | Lc 34.9 | Non-text elements, placeholder text |
| #4273ED text on white | 4.27:1 | AA large text | Lc 69.1 | Content text, not long reading |
| #4273ED text on black | 4.90:1 | AA | Lc -32.5 | 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
#F2F6FE
oklch(97.2% 0.012 264.5)
-
Step 100
100
#E2EAFB
oklch(93.6% 0.025 265.6)
-
Step 200
200
#CAD9FA
oklch(88.5% 0.048 266)
-
Step 300
300
#A5C0F9
oklch(80.8% 0.086 264.8)
-
Step 400
400
#759EF7
oklch(70.8% 0.138 264.4)
-
Step 500
500
#5382F3
oklch(63.1% 0.177 264.8)
-
Step 600
600 (this color)
#4273ED
oklch(58.9% 0.192 264.7)
-
Step 700
700
#2C56C4
oklch(49.1% 0.179 264.7)
-
Step 800
800
#25479E
oklch(42.6% 0.147 264.7)
-
Step 900
900
#223D7E
oklch(37.8% 0.115 264.5)
-
Step 950
950
#14244A
oklch(27% 0.074 264.7)
#4273ED 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) | #2182F1 | 0.039 |
| Deuteranopia (no green cones) | #0073EB | 0.033 |
| Tritanopia (no blue cones) | #0090A5 | 0.152 |
| Achromatopsia (no color) | #7A7A7A | 0.192 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4273ED
#4273ED
oklch(58.9% 0.192 264.7)
- #9E7600
#9E7600
oklch(58.9% 0.121 84.8)
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 #4273ED, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.030
- Clear Blue #247AFD ΔE 0.032
- Cerulean Blue #056EEE ΔE 0.037
- Neon Blue #4361EE ΔE 0.043
- Cornflower #6A79F7 ΔE 0.052
- Bright Blue #0165FC ΔE 0.057
- Azul #1D5DEC ΔE 0.065
- Dark Periwinkle #665FD1 ΔE 0.069
Use #4273ED 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.