#277AC9
Closest named color: Windows Blue (#3778BF). oklch(57.1% 0.145 251.2), rgb(39, 122, 201).
Aa
Black text reads best on this color (4.71:1).
About this color
#277AC9 is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.145 and its hue 251°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.017 away. Black text reads best on it, at 4.71:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.71:1 |
| White text | 4.45:1 |
Values
| HEX | #277AC9 |
| RGB | rgb(39, 122, 201) |
| HSL | hsl(209, 68%, 47%) |
| OKLCH | oklch(57.1% 0.145 251.2) |
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 #277AC9 | 4.45:1 | AA large text | Lc -76.0 | Fine for body text |
| Black text on #277AC9 | 4.71:1 | AA | Lc 33.6 | Non-text elements, placeholder text |
| #277AC9 text on white | 4.45:1 | AA large text | Lc 70.5 | Content text, not long reading |
| #277AC9 text on black | 4.71:1 | AA | Lc -31.2 | 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
#C8DBF1
oklch(88.4% 0.037 252.1)
-
Step 300
300
#A2C4EA
oklch(80.9% 0.065 251.5)
-
Step 400
400
#6EA5E0
oklch(70.8% 0.105 251.1)
-
Step 500
500
#458DD7
oklch(63.1% 0.133 251.3)
-
Step 600
600 (this color)
#277AC9
oklch(57.1% 0.145 251.2)
-
Step 700
700
#1262A9
oklch(49% 0.134 251.2)
-
Step 800
800
#145189
oklch(42.8% 0.11 250.9)
-
Step 900
900
#19436E
oklch(37.7% 0.087 251.7)
-
Step 950
950
#102840
oklch(27.1% 0.054 250.5)
#277AC9 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) | #547FCC | 0.042 |
| Deuteranopia (no green cones) | #3A71C7 | 0.025 |
| Tritanopia (no blue cones) | #008D98 | 0.106 |
| Achromatopsia (no color) | #777777 | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #277AC9
#277AC9
oklch(57.1% 0.145 251.2)
- #A46900
#A46900
oklch(57.1% 0.123 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 #277AC9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.017
- Water Blue #0E87CC ΔE 0.035
- Nice Blue #107AB0 ΔE 0.042
- Steel Blue #4682B4 ΔE 0.050
- Cool Blue #4984B8 ΔE 0.051
- Flat Blue #3C73A8 ΔE 0.051
- Mid Blue #276AB3 ΔE 0.052
- French Blue #436BAD ΔE 0.055
Use #277AC9 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.