#3F37AE
Closest named color: Sapphire (#2138AB). oklch(42.6% 0.182 278.3), rgb(63, 55, 174).
Aa
White text reads best on this color (8.86:1).
About this color
#3F37AE is a dark, vivid blue. In OKLCH its lightness is 43%, its chroma 0.182 and its hue 278°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.039 away. White text reads best on it, at 8.86:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | vivid (0.182) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.36:1 |
| White text | 8.86:1 |
Values
| HEX | #3F37AE |
| RGB | rgb(63, 55, 174) |
| HSL | hsl(244, 52%, 45%) |
| OKLCH | oklch(42.6% 0.182 278.3) |
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 #3F37AE | 8.86:1 | AAA | Lc -94.1 | Preferred for body text |
| Black text on #3F37AE | 2.36:1 | Fails | Lc 14.3 | Not readable |
| #3F37AE text on white | 8.86:1 | AAA | Lc 89.6 | Fine for body text |
| #3F37AE text on black | 2.36:1 | Fails | Lc -12.6 | Not readable |
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 800.
-
Step 50
50
#F3F5FF
oklch(97.2% 0.013 277.1)
-
Step 100
100
#E5E8FF
oklch(93.6% 0.031 279.9)
-
Step 200
200
#D0D6FF
oklch(88.5% 0.057 278.6)
-
Step 300
300
#B2BBFF
oklch(81% 0.097 278.2)
-
Step 400
400
#8C94FF
oklch(70.7% 0.155 278.4)
-
Step 500
500
#7274FF
oklch(63% 0.202 278.3)
-
Step 600
600
#5E53F8
oklch(55.7% 0.236 278.4)
-
Step 700
700
#4E41D8
oklch(49.1% 0.22 278.4)
-
Step 800
800 (this color)
#3F37AE
oklch(42.6% 0.182 278.3)
-
Step 900
900
#35328A
oklch(37.7% 0.142 278.6)
-
Step 950
950
#1E1E51
oklch(26.9% 0.091 278.4)
#3F37AE 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) | #004FB2 | 0.067 |
| Deuteranopia (no green cones) | #0045AC | 0.057 |
| Tritanopia (no blue cones) | #00566E | 0.149 |
| Achromatopsia (no color) | #4A4A4A | 0.182 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F37AE
#3F37AE
oklch(42.6% 0.182 278.3)
- #5B4F00
#5B4F00
oklch(42.7% 0.088 99.2)
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 #3F37AE, closest first.
No curated palette has a color within ΔE 0.04 of #3F37AE.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.039
- Majorelle Blue #3F37C9 ΔE 0.043
- Blueberry #464196 ΔE 0.048
- Indigo Blue #3A18B1 ΔE 0.051
- Blue With A Hint Of Purple #533CC6 ΔE 0.052
- Blue Blue #2242C7 ΔE 0.055
- Blurple #5539CC ΔE 0.060
- Dark Slate Blue #483D8B ΔE 0.061
Use #3F37AE 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.