#4273BF
Closest named color: Windows Blue (#3778BF). oklch(55.8% 0.13 258.9), rgb(66, 115, 191).
Aa
White text reads best on this color (4.73:1).
About this color
#4273BF is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.130 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.015 away. White text reads best on it, at 4.73:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.130) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.43:1 |
| White text | 4.73:1 |
Values
| HEX | #4273BF |
| RGB | rgb(66, 115, 191) |
| HSL | hsl(216, 49%, 50%) |
| OKLCH | oklch(55.8% 0.13 258.9) |
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 #4273BF | 4.73:1 | AA | Lc -78.1 | Fine for body text |
| Black text on #4273BF | 4.43:1 | AA large text | Lc 31.5 | Non-text elements, placeholder text |
| #4273BF text on white | 4.73:1 | AA | Lc 72.6 | Content text, not long reading |
| #4273BF text on black | 4.43:1 | AA large text | Lc -29.1 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EAF5
oklch(93.5% 0.017 259.4)
-
Step 200
200
#CCDAEF
oklch(88.4% 0.033 258.4)
-
Step 300
300
#AAC2E7
oklch(80.9% 0.059 259)
-
Step 400
400
#7DA2DB
oklch(70.7% 0.093 258.8)
-
Step 500
500
#5C8AD1
oklch(63.2% 0.119 258.8)
-
Step 600
600 (this color)
#4273BF
oklch(55.8% 0.13 258.9)
-
Step 700
700
#3360A4
oklch(49.2% 0.12 258.5)
-
Step 800
800
#2B4E85
oklch(42.6% 0.1 259.1)
-
Step 900
900
#27416B
oklch(37.6% 0.079 259.6)
-
Step 950
950
#17273E
oklch(27.1% 0.048 257.5)
#4273BF 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) | #5179C2 | 0.025 |
| Deuteranopia (no green cones) | #3E6EBD | 0.015 |
| Tritanopia (no blue cones) | #008490 | 0.105 |
| Achromatopsia (no color) | #737373 | 0.130 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4273BF
#4273BF
oklch(55.8% 0.13 258.9)
- #986A00
#986A00
oklch(55.8% 0.116 78.7)
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 #4273BF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.015
- French Blue #436BAD ΔE 0.033
- Flat Blue #3C73A8 ΔE 0.037
- Mid Blue #276AB3 ΔE 0.040
- Nice Blue #107AB0 ΔE 0.045
- Steel Blue #4682B4 ΔE 0.050
- Muted Blue #3B719F ΔE 0.051
- Cool Blue #4984B8 ΔE 0.053
Use #4273BF 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.