#4273AC
Closest named color: Flat Blue (#3C73A8). oklch(54.7% 0.104 253.4), rgb(66, 115, 172).
Aa
White text reads best on this color (4.90:1).
About this color
#4273AC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.104 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Flat Blue (#3C73A8), ΔE 0.009 away. White text reads best on it, at 4.90:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.104) |
| Temperature | cool |
| Nearest name | Flat Blue (#3C73A8) |
| Black text | 4.27:1 |
| White text | 4.90:1 |
Values
| HEX | #4273AC |
| RGB | rgb(66, 115, 172) |
| HSL | hsl(212, 45%, 47%) |
| OKLCH | oklch(54.7% 0.104 253.4) |
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 #4273AC | 4.90:1 | AA | Lc -79.2 | Fine for body text |
| Black text on #4273AC | 4.27:1 | AA large text | Lc 30.3 | Non-text elements, placeholder text |
| #4273AC text on white | 4.90:1 | AA | Lc 73.8 | Content text, not long reading |
| #4273AC text on black | 4.27:1 | AA large text | Lc -27.9 | 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
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E4EBF3
oklch(93.7% 0.013 251.6)
-
Step 200
200
#CEDBEA
oklch(88.6% 0.025 251.9)
-
Step 300
300
#ACC3DF
oklch(80.9% 0.047 253.5)
-
Step 400
400
#80A4CF
oklch(70.8% 0.075 253.2)
-
Step 500
500
#5F8CC2
oklch(63% 0.096 253.7)
-
Step 600
600 (this color)
#4273AC
oklch(54.7% 0.104 253.4)
-
Step 700
700
#366396
oklch(49.2% 0.096 252.9)
-
Step 800
800
#2D517A
oklch(42.8% 0.08 252.9)
-
Step 900
900
#294362
oklch(37.7% 0.062 253.6)
-
Step 950
950
#182739
oklch(26.8% 0.04 253.6)
#4273AC 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) | #5B76AE | 0.031 |
| Deuteranopia (no green cones) | #4D6CAB | 0.021 |
| Tritanopia (no blue cones) | #008087 | 0.087 |
| Achromatopsia (no color) | #717171 | 0.104 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4273AC
#4273AC
oklch(54.7% 0.104 253.4)
- #95661D
#95661D
oklch(54.7% 0.104 73.3)
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 #4273AC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Flat Blue #3C73A8 ΔE 0.009
- Muted Blue #3B719F ΔE 0.022
- French Blue #436BAD ΔE 0.023
- Dull Blue #49759C ΔE 0.028
- Windows Blue #3778BF ΔE 0.030
- Nice Blue #107AB0 ΔE 0.032
- Cerulean #457B9D ΔE 0.038
- Mid Blue #276AB3 ΔE 0.040
Use #4273AC 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.