#3998EE
Closest named color: Chefchaouen Blue (#4895EF). oklch(66.5% 0.155 249.6), rgb(57, 152, 238).
Aa
Black text reads best on this color (6.89:1).
About this color
#3998EE is a medium-light, vivid blue. In OKLCH its lightness is 66%, its chroma 0.155 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Chefchaouen Blue (#4895EF), ΔE 0.012 away. Black text reads best on it, at 6.89:1.
| Hue family | Blues |
| Lightness | medium-light (66%) |
| Chroma | vivid (0.155) |
| Temperature | cool |
| Nearest name | Chefchaouen Blue (#4895EF) |
| Black text | 6.89:1 |
| White text | 3.04:1 |
Values
| HEX | #3998EE |
| RGB | rgb(57, 152, 238) |
| HSL | hsl(209, 84%, 58%) |
| OKLCH | oklch(66.5% 0.155 249.6) |
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 #3998EE | 3.04:1 | AA large text | Lc -62.2 | Content text, not long reading |
| Black text on #3998EE | 6.89:1 | AA | Lc 47.2 | Large or bold text, headings |
| #3998EE text on white | 3.04:1 | AA large text | Lc 56.8 | Large or bold text, headings |
| #3998EE text on black | 6.89:1 | AA | Lc -44.9 | 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
#F0F6FC
oklch(97% 0.01 247.9)
-
Step 100
100
#DFEBF8
oklch(93.5% 0.022 250.2)
-
Step 200
200
#C5DCF5
oklch(88.5% 0.042 250.5)
-
Step 300
300
#9BC5F0
oklch(80.9% 0.076 249.4)
-
Step 400
400
#61A6E9
oklch(70.8% 0.121 249.2)
-
Step 500
500 (this color)
#3998EE
oklch(66.5% 0.155 249.6)
-
Step 600
600
#0076C9
oklch(55.6% 0.155 249.4)
-
Step 700
700
#0063AA
oklch(49.1% 0.137 249.4)
-
Step 800
800
#00518D
oklch(42.7% 0.12 249.5)
-
Step 900
900
#064374
oklch(37.6% 0.101 249.7)
-
Step 950
950
#082844
oklch(27% 0.064 249)
#3998EE 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) | #709DF2 | 0.052 |
| Deuteranopia (no green cones) | #558CEC | 0.035 |
| Tritanopia (no blue cones) | #00ADB8 | 0.115 |
| Achromatopsia (no color) | #949494 | 0.155 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3998EE
#3998EE
oklch(66.5% 0.155 249.6)
- #CB8100
#CB8100
oklch(66.5% 0.144 69.8)
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 #3998EE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Chefchaouen Blue #4895EF ΔE 0.012
- Dark Sky Blue #448EE4 ΔE 0.028
- Cornflower Blue #6495ED ΔE 0.035
- Dodger Blue #1E90FF ΔE 0.039
- Soft Blue #6488EA ΔE 0.050
- Water Blue #0E87CC ΔE 0.070
- Faded Blue #658CBB ΔE 0.080
- Clear Blue #247AFD ΔE 0.087
Use #3998EE 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.