#277BBF
Closest named color: Windows Blue (#3778BF). oklch(56.7% 0.131 247.6), rgb(39, 123, 191).
Aa
Black text reads best on this color (4.67:1).
About this color
#277BBF is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.131 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.012 away. Black text reads best on it, at 4.67:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.131) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.67:1 |
| White text | 4.49:1 |
Values
| HEX | #277BBF |
| RGB | rgb(39, 123, 191) |
| HSL | hsl(207, 66%, 45%) |
| OKLCH | oklch(56.7% 0.131 247.6) |
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 #277BBF | 4.49:1 | AA large text | Lc -76.3 | Fine for body text |
| Black text on #277BBF | 4.67:1 | AA | Lc 33.3 | Non-text elements, placeholder text |
| #277BBF text on white | 4.49:1 | AA large text | Lc 70.8 | Content text, not long reading |
| #277BBF text on black | 4.67:1 | AA | Lc -30.9 | 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
#E1EBF5
oklch(93.5% 0.017 248)
-
Step 200
200
#C9DCEE
oklch(88.6% 0.032 246.7)
-
Step 300
300
#A3C5E5
oklch(80.9% 0.058 247)
-
Step 400
400
#6FA6D9
oklch(70.7% 0.095 247.5)
-
Step 500
500
#468FCE
oklch(63.1% 0.12 247.2)
-
Step 600
600 (this color)
#277BBF
oklch(56.7% 0.131 247.6)
-
Step 700
700
#1364A2
oklch(49% 0.123 247.9)
-
Step 800
800
#155283
oklch(42.7% 0.101 247.8)
-
Step 900
900
#194469
oklch(37.6% 0.079 247.8)
-
Step 950
950
#10283D
oklch(26.9% 0.05 247.3)
#277BBF 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) | #5B7EC2 | 0.048 |
| Deuteranopia (no green cones) | #4571BE | 0.033 |
| Tritanopia (no blue cones) | #008B94 | 0.093 |
| Achromatopsia (no color) | #777777 | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #277BBF
#277BBF
oklch(56.7% 0.131 247.6)
- #A66600
#A66600
oklch(56.8% 0.125 67.8)
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 #277BBF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.012
- Nice Blue #107AB0 ΔE 0.027
- Water Blue #0E87CC ΔE 0.035
- Steel Blue #4682B4 ΔE 0.038
- Flat Blue #3C73A8 ΔE 0.038
- Cool Blue #4984B8 ΔE 0.042
- French Blue #436BAD ΔE 0.048
- Mid Blue #276AB3 ΔE 0.049
Use #277BBF 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.