#3991FC
Closest named color: Dodger Blue (#1E90FF). oklch(65.8% 0.18 255.5), rgb(57, 145, 252).
Aa
Black text reads best on this color (6.62:1).
About this color
#3991FC is a medium-light, vivid blue. In OKLCH its lightness is 66%, its chroma 0.180 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Dodger Blue (#1E90FF), ΔE 0.014 away. Black text reads best on it, at 6.62:1.
| Hue family | Blues |
| Lightness | medium-light (66%) |
| Chroma | vivid (0.180) |
| Temperature | cool |
| Nearest name | Dodger Blue (#1E90FF) |
| Black text | 6.62:1 |
| White text | 3.16:1 |
Values
| HEX | #3991FC |
| RGB | rgb(57, 145, 252) |
| HSL | hsl(213, 97%, 61%) |
| OKLCH | oklch(65.8% 0.18 255.5) |
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 #3991FC | 3.16:1 | AA large text | Lc -63.7 | Content text, not long reading |
| Black text on #3991FC | 6.62:1 | AA | Lc 45.7 | Large or bold text, headings |
| #3991FC text on white | 3.16:1 | AA large text | Lc 58.3 | Large or bold text, headings |
| #3991FC text on black | 6.62:1 | AA | Lc -43.4 | 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 500.
-
Step 50
50
#F0F6FD
oklch(97.1% 0.011 252.1)
-
Step 100
100
#DFEBFB
oklch(93.6% 0.025 255.6)
-
Step 200
200
#C4DBFA
oklch(88.4% 0.05 255.9)
-
Step 300
300
#9BC4F9
oklch(81% 0.087 255.1)
-
Step 400
400
#61A2F6
oklch(70.6% 0.141 255.5)
-
Step 500
500 (this color)
#3991FC
oklch(65.8% 0.18 255.5)
-
Step 600
600
#0070DC
oklch(55.6% 0.186 255.4)
-
Step 700
700
#005EBB
oklch(49.1% 0.165 255.5)
-
Step 800
800
#004D9A
oklch(42.7% 0.142 255.2)
-
Step 900
900
#09407E
oklch(37.6% 0.118 255.6)
-
Step 950
950
#09264A
oklch(27% 0.075 255.8)
#3991FC 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) | #5B9AFF | 0.039 |
| Deuteranopia (no green cones) | #3688FA | 0.024 |
| Tritanopia (no blue cones) | #00AABA | 0.136 |
| Achromatopsia (no color) | #919191 | 0.180 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3991FC
#3991FC
oklch(65.8% 0.18 255.5)
- #C28300
#C28300
oklch(65.8% 0.139 75.1)
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 #3991FC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dodger Blue #1E90FF ΔE 0.014
- Chefchaouen Blue #4895EF ΔE 0.026
- Dark Sky Blue #448EE4 ΔE 0.035
- Soft Blue #6488EA ΔE 0.045
- Cornflower Blue #6495ED ΔE 0.045
- Clear Blue #247AFD ΔE 0.063
- Cornflower #6A79F7 ΔE 0.068
- Water Blue #0E87CC ΔE 0.079
Use #3991FC 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.