#2578C5
Closest named color: Windows Blue (#3778BF). oklch(56.3% 0.142 250.8), rgb(37, 120, 197).
Aa
White text reads best on this color (4.59:1).
About this color
#2578C5 is a medium-dark, vivid blue. In OKLCH its lightness is 56%, its chroma 0.142 and its hue 251°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.014 away. White text reads best on it, at 4.59:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | vivid (0.142) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.57:1 |
| White text | 4.59:1 |
Values
| HEX | #2578C5 |
| RGB | rgb(37, 120, 197) |
| HSL | hsl(209, 68%, 46%) |
| OKLCH | oklch(56.3% 0.142 250.8) |
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 #2578C5 | 4.59:1 | AA | Lc -76.9 | Fine for body text |
| Black text on #2578C5 | 4.57:1 | AA | Lc 32.6 | Non-text elements, placeholder text |
| #2578C5 text on white | 4.59:1 | AA | Lc 71.5 | Content text, not long reading |
| #2578C5 text on black | 4.57:1 | AA | Lc -30.2 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF6
oklch(93.6% 0.018 250.6)
-
Step 200
200
#C8DBF0
oklch(88.4% 0.036 250.9)
-
Step 300
300
#A2C4E9
oklch(80.8% 0.064 250.8)
-
Step 400
400
#6FA5DE
oklch(70.7% 0.102 250.7)
-
Step 500
500
#468DD5
oklch(63.1% 0.13 250.9)
-
Step 600
600 (this color)
#2578C5
oklch(56.3% 0.142 250.8)
-
Step 700
700
#1363A8
oklch(49.2% 0.132 250.5)
-
Step 800
800
#145188
oklch(42.7% 0.109 250.5)
-
Step 900
900
#19436D
oklch(37.6% 0.086 251.2)
-
Step 950
950
#102840
oklch(27.1% 0.054 250.5)
#2578C5 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) | #537DC8 | 0.043 |
| Deuteranopia (no green cones) | #396FC3 | 0.025 |
| Tritanopia (no blue cones) | #008A95 | 0.103 |
| Achromatopsia (no color) | #757575 | 0.142 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #2578C5
#2578C5
oklch(56.3% 0.142 250.8)
- #A16700
#A16700
oklch(56.3% 0.121 71.1)
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 #2578C5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.014
- Nice Blue #107AB0 ΔE 0.036
- Water Blue #0E87CC ΔE 0.041
- Mid Blue #276AB3 ΔE 0.044
- Flat Blue #3C73A8 ΔE 0.045
- French Blue #436BAD ΔE 0.048
- Steel Blue #4682B4 ΔE 0.051
- Cool Blue #4984B8 ΔE 0.053
Use #2578C5 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.