#277ECA
Closest named color: Windows Blue (#3778BF). oklch(58% 0.142 249.5), rgb(39, 126, 202).
Aa
Black text reads best on this color (4.92:1).
About this color
#277ECA is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.142 and its hue 249°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.022 away. Black text reads best on it, at 4.92:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.142) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.92:1 |
| White text | 4.26:1 |
Values
| HEX | #277ECA |
| RGB | rgb(39, 126, 202) |
| HSL | hsl(208, 68%, 47%) |
| OKLCH | oklch(58% 0.142 249.5) |
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 #277ECA | 4.26:1 | AA large text | Lc -74.5 | Content text, not long reading |
| Black text on #277ECA | 4.92:1 | AA | Lc 35.0 | Non-text elements, placeholder text |
| #277ECA text on white | 4.26:1 | AA large text | Lc 69.0 | Content text, not long reading |
| #277ECA text on black | 4.92:1 | AA | Lc -32.6 | 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
#C8DCF0
oklch(88.6% 0.035 248.2)
-
Step 300
300
#A2C5E9
oklch(81% 0.063 249.3)
-
Step 400
400
#6DA5DE
oklch(70.6% 0.103 249.9)
-
Step 500
500
#438ED5
oklch(63.2% 0.131 249.6)
-
Step 600
600 (this color)
#277ECA
oklch(58% 0.142 249.5)
-
Step 700
700
#0C63A7
oklch(49% 0.132 249.5)
-
Step 800
800
#115188
oklch(42.7% 0.11 249.9)
-
Step 900
900
#17446D
oklch(37.8% 0.086 249.5)
-
Step 950
950
#0F2840
oklch(27% 0.055 249.7)
#277ECA 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) | #5A82CD | 0.046 |
| Deuteranopia (no green cones) | #4174C9 | 0.030 |
| Tritanopia (no blue cones) | #00909A | 0.103 |
| Achromatopsia (no color) | #7A7A7A | 0.142 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #277ECA
#277ECA
oklch(58% 0.142 249.5)
- #A96A00
#A96A00
oklch(57.9% 0.126 69.3)
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 #277ECA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.022
- Water Blue #0E87CC ΔE 0.025
- Nice Blue #107AB0 ΔE 0.043
- Steel Blue #4682B4 ΔE 0.044
- Cool Blue #4984B8 ΔE 0.044
- Flat Blue #3C73A8 ΔE 0.055
- Blue NCS #118AB2 ΔE 0.057
- Dark Sky Blue #448EE4 ΔE 0.062
Use #277ECA 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.