#1F66EB
Closest named color: Cerulean Blue (#056EEE). oklch(55.1% 0.213 261.6), rgb(31, 102, 235).
Aa
White text reads best on this color (5.04:1).
About this color
#1F66EB is a medium-dark, vivid blue. In OKLCH its lightness is 55%, its chroma 0.213 and its hue 262°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean Blue (#056EEE), ΔE 0.019 away. White text reads best on it, at 5.04:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | vivid (0.213) |
| Temperature | cool |
| Nearest name | Cerulean Blue (#056EEE) |
| Black text | 4.15:1 |
| White text | 5.04:1 |
Values
| HEX | #1F66EB |
| RGB | rgb(31, 102, 235) |
| HSL | hsl(219, 84%, 52%) |
| OKLCH | oklch(55.1% 0.213 261.6) |
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 #1F66EB | 5.04:1 | AA | Lc -79.5 | Fine for body text |
| Black text on #1F66EB | 4.15:1 | AA large text | Lc 29.9 | Dividers and decoration only |
| #1F66EB text on white | 5.04:1 | AA | Lc 74.1 | Content text, not long reading |
| #1F66EB text on black | 4.15:1 | AA large text | Lc -27.6 | Dividers and decoration only |
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
#E0EAFD
oklch(93.5% 0.028 263.4)
-
Step 200
200
#C6DAFD
oklch(88.5% 0.053 261.7)
-
Step 300
300
#9EC1FF
oklch(80.8% 0.096 261.6)
-
Step 400
400
#6A9EFF
oklch(70.6% 0.153 261.9)
-
Step 500
500
#4182FE
oklch(63.1% 0.197 261.7)
-
Step 600
600 (this color)
#1F66EB
oklch(55.1% 0.213 261.6)
-
Step 700
700
#1455CE
oklch(49.1% 0.198 261.6)
-
Step 800
800
#1347A7
oklch(42.8% 0.164 261.4)
-
Step 900
900
#173D84
oklch(37.8% 0.127 261.5)
-
Step 950
950
#0E244D
oklch(26.9% 0.081 261.5)
#1F66EB 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) | #0078F0 | 0.043 |
| Deuteranopia (no green cones) | #0066E8 | 0.011 |
| Tritanopia (no blue cones) | #00889F | 0.163 |
| Achromatopsia (no color) | #6F6F6F | 0.213 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F66EB
#1F66EB
oklch(55.1% 0.213 261.6)
- #936A00
#936A00
oklch(55.2% 0.114 81.8)
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 #1F66EB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean Blue #056EEE ΔE 0.019
- Azul #1D5DEC ΔE 0.021
- Bright Blue #0165FC ΔE 0.027
- Neon Blue #4361EE ΔE 0.028
- Royal Blue #4169E1 ΔE 0.031
- Warm Blue #4B57DB ΔE 0.051
- Electric Blue #0652FF ΔE 0.054
- Clear Blue #247AFD ΔE 0.056
Use #1F66EB 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.