#4275CF
Closest named color: Windows Blue (#3778BF). oklch(57.3% 0.149 260.9), rgb(66, 117, 207).
Aa
Black text reads best on this color (4.67:1).
About this color
#4275CF is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.149 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.029 away. Black text reads best on it, at 4.67:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.149) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.67:1 |
| White text | 4.48:1 |
Values
| HEX | #4275CF |
| RGB | rgb(66, 117, 207) |
| HSL | hsl(218, 59%, 54%) |
| OKLCH | oklch(57.3% 0.149 260.9) |
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 #4275CF | 4.48:1 | AA large text | Lc -76.3 | Fine for body text |
| Black text on #4275CF | 4.67:1 | AA | Lc 33.2 | Non-text elements, placeholder text |
| #4275CF text on white | 4.48:1 | AA large text | Lc 70.9 | Content text, not long reading |
| #4275CF text on black | 4.67:1 | AA | Lc -30.8 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CBDAF3
oklch(88.5% 0.038 260.7)
-
Step 300
300
#A8C2ED
oklch(80.9% 0.067 260.4)
-
Step 400
400
#7AA1E4
oklch(70.7% 0.108 260.9)
-
Step 500
500
#5888DC
oklch(63.1% 0.137 260.9)
-
Step 600
600 (this color)
#4275CF
oklch(57.3% 0.149 260.9)
-
Step 700
700
#2F5DAE
oklch(49% 0.139 260.8)
-
Step 800
800
#284D8D
oklch(42.8% 0.114 260.6)
-
Step 900
900
#254071
oklch(37.7% 0.09 261.4)
-
Step 950
950
#162642
oklch(27% 0.057 260.9)
#4275CF 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) | #4A7ED2 | 0.027 |
| Deuteranopia (no green cones) | #3171CD | 0.020 |
| Tritanopia (no blue cones) | #008A98 | 0.121 |
| Achromatopsia (no color) | #777777 | 0.149 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4275CF
#4275CF
oklch(57.3% 0.149 260.9)
- #9C6F00
#9C6F00
oklch(57.3% 0.118 80.4)
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 #4275CF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.029
- Royal Blue #4169E1 ΔE 0.044
- Water Blue #0E87CC ΔE 0.053
- French Blue #436BAD ΔE 0.055
- Mid Blue #276AB3 ΔE 0.058
- Cool Blue #4984B8 ΔE 0.061
- Steel Blue #4682B4 ΔE 0.061
- Flat Blue #3C73A8 ΔE 0.061
Use #4275CF 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.