#3770EC
Closest named color: Royal Blue (#4169E1). oklch(57.8% 0.197 263.1), rgb(55, 112, 236).
Aa
Black text reads best on this color (4.69:1).
About this color
#3770EC is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.197 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.023 away. Black text reads best on it, at 4.69:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.197) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.69:1 |
| White text | 4.47:1 |
Values
| HEX | #3770EC |
| RGB | rgb(55, 112, 236) |
| HSL | hsl(221, 83%, 57%) |
| OKLCH | oklch(57.8% 0.197 263.1) |
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 #3770EC | 4.47:1 | AA large text | Lc -76.0 | Fine for body text |
| Black text on #3770EC | 4.69:1 | AA | Lc 33.5 | Non-text elements, placeholder text |
| #3770EC text on white | 4.47:1 | AA large text | Lc 70.5 | Content text, not long reading |
| #3770EC text on black | 4.69:1 | AA | Lc -31.1 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E1EAFC
oklch(93.6% 0.026 264.4)
-
Step 200
200
#C8DAFB
oklch(88.5% 0.05 262.6)
-
Step 300
300
#A3C1FB
oklch(81% 0.089 263.3)
-
Step 400
400
#719EF9
oklch(70.7% 0.143 263.3)
-
Step 500
500
#4C83F5
oklch(63.1% 0.181 262.9)
-
Step 600
600 (this color)
#3770EC
oklch(57.8% 0.197 263.1)
-
Step 700
700
#2456C6
oklch(49% 0.183 263.2)
-
Step 800
800
#1F47A0
oklch(42.6% 0.152 263.2)
-
Step 900
900
#1E3D7F
oklch(37.7% 0.118 263)
-
Step 950
950
#12244B
oklch(26.9% 0.076 263.5)
#3770EC 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) | #0E80F0 | 0.040 |
| Deuteranopia (no green cones) | #006FEA | 0.025 |
| Tritanopia (no blue cones) | #008EA3 | 0.154 |
| Achromatopsia (no color) | #777777 | 0.197 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3770EC
#3770EC
oklch(57.8% 0.197 263.1)
- #9B7200
#9B7200
oklch(57.8% 0.119 83.4)
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 #3770EC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.023
- Cerulean Blue #056EEE ΔE 0.025
- Clear Blue #247AFD ΔE 0.034
- Neon Blue #4361EE ΔE 0.035
- Bright Blue #0165FC ΔE 0.046
- Azul #1D5DEC ΔE 0.052
- Warm Blue #4B57DB ΔE 0.062
- Cornflower #6A79F7 ΔE 0.064
Use #3770EC 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.