#4573BB
Closest named color: Windows Blue (#3778BF). oklch(55.7% 0.123 259), rgb(69, 115, 187).
Aa
White text reads best on this color (4.74:1).
About this color
#4573BB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.123 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.017 away. White text reads best on it, at 4.74:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.123) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.42:1 |
| White text | 4.74:1 |
Values
| HEX | #4573BB |
| RGB | rgb(69, 115, 187) |
| HSL | hsl(217, 46%, 50%) |
| OKLCH | oklch(55.7% 0.123 259) |
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 #4573BB | 4.74:1 | AA | Lc -78.2 | Fine for body text |
| Black text on #4573BB | 4.42:1 | AA large text | Lc 31.3 | Non-text elements, placeholder text |
| #4573BB text on white | 4.74:1 | AA | Lc 72.7 | Content text, not long reading |
| #4573BB text on black | 4.42:1 | AA large text | Lc -28.9 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E4EAF5
oklch(93.6% 0.016 262.8)
-
Step 200
200
#CDDAEE
oklch(88.5% 0.031 258.9)
-
Step 300
300
#ABC2E5
oklch(80.9% 0.056 258.7)
-
Step 400
400
#7FA2D8
oklch(70.7% 0.089 258.9)
-
Step 500
500
#5E8ACE
oklch(63.1% 0.114 258.8)
-
Step 600
600 (this color)
#4573BB
oklch(55.7% 0.123 259)
-
Step 700
700
#3660A1
oklch(49.1% 0.115 258.9)
-
Step 800
800
#2D4E82
oklch(42.6% 0.095 259.1)
-
Step 900
900
#294269
oklch(37.9% 0.074 259)
-
Step 950
950
#18273D
oklch(27.1% 0.046 257.8)
#4573BB 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) | #5479BE | 0.025 |
| Deuteranopia (no green cones) | #436EBA | 0.014 |
| Tritanopia (no blue cones) | #00838E | 0.102 |
| Achromatopsia (no color) | #737373 | 0.123 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4573BB
#4573BB
oklch(55.7% 0.123 259)
- #976A00
#976A00
oklch(55.7% 0.116 79.3)
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 #4573BB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.017
- French Blue #436BAD ΔE 0.029
- Flat Blue #3C73A8 ΔE 0.032
- Mid Blue #276AB3 ΔE 0.040
- Nice Blue #107AB0 ΔE 0.043
- Muted Blue #3B719F ΔE 0.046
- Steel Blue #4682B4 ΔE 0.047
- Cool Blue #4984B8 ΔE 0.050
Use #4573BB 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.