#3F55BC
Closest named color: Warm Blue (#4B57DB). oklch(49.1% 0.164 270.2), rgb(63, 85, 188).
Aa
White text reads best on this color (6.48:1).
About this color
#3F55BC is a medium-dark, vivid blue. In OKLCH its lightness is 49%, its chroma 0.164 and its hue 270°. Its hue sits on the cool side of the wheel. The nearest named color is Warm Blue (#4B57DB), ΔE 0.051 away. White text reads best on it, at 6.48:1.
| Hue family | Blues |
| Lightness | medium-dark (49%) |
| Chroma | vivid (0.164) |
| Temperature | cool |
| Nearest name | Warm Blue (#4B57DB) |
| Black text | 3.23:1 |
| White text | 6.48:1 |
Values
| HEX | #3F55BC |
| RGB | rgb(63, 85, 188) |
| HSL | hsl(229, 50%, 49%) |
| OKLCH | oklch(49.1% 0.164 270.2) |
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 #3F55BC | 6.48:1 | AA | Lc -86.9 | Fine for body text |
| Black text on #3F55BC | 3.23:1 | AA large text | Lc 22.3 | Dividers and decoration only |
| #3F55BC text on white | 6.48:1 | AA | Lc 81.8 | Fine for body text |
| #3F55BC text on black | 3.23:1 | AA large text | Lc -20.1 | 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
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E4EAFA
oklch(93.7% 0.023 269.4)
-
Step 200
200
#CED8F7
oklch(88.4% 0.044 271.3)
-
Step 300
300
#ADBFF5
oklch(81% 0.079 270.3)
-
Step 400
400
#829CF0
oklch(70.8% 0.127 269.9)
-
Step 500
500
#6580EA
oklch(63% 0.162 270.5)
-
Step 600
600
#4D67D9
oklch(55.6% 0.177 270.1)
-
Step 700
700 (this color)
#3F55BC
oklch(49.1% 0.164 270.2)
-
Step 800
800
#344698
oklch(42.7% 0.135 270.4)
-
Step 900
900
#2D3C79
oklch(37.8% 0.105 270.3)
-
Step 950
950
#1A2347
oklch(26.9% 0.068 270.7)
#3F55BC 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) | #0164C0 | 0.048 |
| Deuteranopia (no green cones) | #0059BA | 0.041 |
| Tritanopia (no blue cones) | #006E80 | 0.136 |
| Achromatopsia (no color) | #5E5E5E | 0.164 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F55BC
#3F55BC
oklch(49.1% 0.164 270.2)
- #775D00
#775D00
oklch(49.1% 0.1 89.6)
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 #3F55BC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Warm Blue #4B57DB ΔE 0.051
- Iris #6258C4 ΔE 0.052
- Blue With A Hint Of Purple #533CC6 ΔE 0.060
- Mid Blue #276AB3 ΔE 0.060
- Blue Blue #2242C7 ΔE 0.061
- Bluey Purple #6241C7 ΔE 0.065
- French Blue #436BAD ΔE 0.068
- Blurple #5539CC ΔE 0.068
Use #3F55BC 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.