#3F5FCB
Closest named color: Warm Blue (#4B57DB). oklch(52.3% 0.172 267.6), rgb(63, 95, 203).
Aa
White text reads best on this color (5.65:1).
About this color
#3F5FCB is a medium-dark, vivid blue. In OKLCH its lightness is 52%, its chroma 0.172 and its hue 268°. Its hue sits on the cool side of the wheel. The nearest named color is Warm Blue (#4B57DB), ΔE 0.034 away. White text reads best on it, at 5.65:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | vivid (0.172) |
| Temperature | cool |
| Nearest name | Warm Blue (#4B57DB) |
| Black text | 3.71:1 |
| White text | 5.65:1 |
Values
| HEX | #3F5FCB |
| RGB | rgb(63, 95, 203) |
| HSL | hsl(226, 57%, 52%) |
| OKLCH | oklch(52.3% 0.172 267.6) |
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 #3F5FCB | 5.65:1 | AA | Lc -83.2 | Fine for body text |
| Black text on #3F5FCB | 3.71:1 | AA large text | Lc 26.2 | Dividers and decoration only |
| #3F5FCB text on white | 5.65:1 | AA | Lc 77.9 | Fine for body text |
| #3F5FCB text on black | 3.71:1 | AA large text | Lc -23.9 | 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 700.
-
Step 50
50
#F2F5FD
oklch(97% 0.011 269.6)
-
Step 100
100
#E3EAFB
oklch(93.7% 0.024 267.9)
-
Step 200
200
#CCD9F9
oklch(88.6% 0.046 267.9)
-
Step 300
300
#A9BFF7
oklch(80.8% 0.083 267.9)
-
Step 400
400
#7C9CF3
oklch(70.6% 0.133 267.6)
-
Step 500
500
#5D81EF
oklch(63.1% 0.17 267.7)
-
Step 600
600
#4567DE
oklch(55.6% 0.186 267.9)
-
Step 700
700 (this color)
#3F5FCB
oklch(52.3% 0.172 267.6)
-
Step 800
800
#2D469C
oklch(42.6% 0.143 267.7)
-
Step 900
900
#283C7C
oklch(37.7% 0.111 267.7)
-
Step 950
950
#172448
oklch(27% 0.069 266.8)
#3F5FCB 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) | #116ECF | 0.043 |
| Deuteranopia (no green cones) | #0061C9 | 0.037 |
| Tritanopia (no blue cones) | #00798C | 0.139 |
| Achromatopsia (no color) | #676767 | 0.172 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F5FCB
#3F5FCB
oklch(52.3% 0.172 267.6)
- #846500
#846500
oklch(52.3% 0.107 87.5)
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 #3F5FCB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Warm Blue #4B57DB ΔE 0.034
- Royal Blue #4169E1 ΔE 0.041
- Iris #6258C4 ΔE 0.047
- Dark Periwinkle #665FD1 ΔE 0.052
- Mid Blue #276AB3 ΔE 0.054
- Neon Blue #4361EE ΔE 0.054
- Azul #1D5DEC ΔE 0.057
- Slate Blue #6A5ACD ΔE 0.057
Use #3F5FCB 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.