#3777D8
Closest named color: Royal Blue (#4169E1). oklch(57.8% 0.163 258.7), rgb(55, 119, 216).
Aa
Black text reads best on this color (4.79:1).
About this color
#3777D8 is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.163 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.039 away. Black text reads best on it, at 4.79:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.163) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.79:1 |
| White text | 4.38:1 |
Values
| HEX | #3777D8 |
| RGB | rgb(55, 119, 216) |
| HSL | hsl(216, 67%, 53%) |
| OKLCH | oklch(57.8% 0.163 258.7) |
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 #3777D8 | 4.38:1 | AA large text | Lc -75.5 | Fine for body text |
| Black text on #3777D8 | 4.79:1 | AA | Lc 34.1 | Non-text elements, placeholder text |
| #3777D8 text on white | 4.38:1 | AA large text | Lc 70.0 | Content text, not long reading |
| #3777D8 text on black | 4.79:1 | AA | Lc -31.7 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C9DAF5
oklch(88.4% 0.042 259.6)
-
Step 300
300
#A4C2F0
oklch(80.8% 0.073 258.8)
-
Step 400
400
#73A2E9
oklch(70.8% 0.116 258.4)
-
Step 500
500
#4D88E2
oklch(63% 0.15 258.6)
-
Step 600
600 (this color)
#3777D8
oklch(57.8% 0.163 258.7)
-
Step 700
700
#235DB5
oklch(49.1% 0.152 258.9)
-
Step 800
800
#1E4D92
oklch(42.8% 0.125 258.4)
-
Step 900
900
#1E4074
oklch(37.5% 0.098 258.7)
-
Step 950
950
#132644
oklch(27% 0.061 259.2)
#3777D8 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) | #4580DC | 0.029 |
| Deuteranopia (no green cones) | #2272D6 | 0.021 |
| Tritanopia (no blue cones) | #008E9D | 0.127 |
| Achromatopsia (no color) | #797979 | 0.163 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3777D8
#3777D8
oklch(57.8% 0.163 258.7)
- #A07000
#A07000
oklch(58% 0.12 78.9)
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 #3777D8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.039
- Windows Blue #3778BF ΔE 0.039
- Cerulean Blue #056EEE ΔE 0.049
- Water Blue #0E87CC ΔE 0.051
- Clear Blue #247AFD ΔE 0.056
- Dark Sky Blue #448EE4 ΔE 0.065
- Neon Blue #4361EE ΔE 0.065
- Mid Blue #276AB3 ΔE 0.067
Use #3777D8 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.