#3975D0
Closest named color: Windows Blue (#3778BF). oklch(57% 0.154 258.7), rgb(57, 117, 208).
Aa
Black text reads best on this color (4.62:1).
About this color
#3975D0 is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.154 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.029 away. Black text reads best on it, at 4.62:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.154) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.62:1 |
| White text | 4.53:1 |
Values
| HEX | #3975D0 |
| RGB | rgb(57, 117, 208) |
| HSL | hsl(216, 62%, 52%) |
| OKLCH | oklch(57% 0.154 258.7) |
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 #3975D0 | 4.53:1 | AA | Lc -76.6 | Fine for body text |
| Black text on #3975D0 | 4.62:1 | AA | Lc 32.9 | Non-text elements, placeholder text |
| #3975D0 text on white | 4.53:1 | AA | Lc 71.1 | Content text, not long reading |
| #3975D0 text on black | 4.62:1 | AA | Lc -30.5 | 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 600.
-
Step 50
50
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EBF8
oklch(93.7% 0.02 257.5)
-
Step 200
200
#CADAF3
oklch(88.4% 0.039 259.3)
-
Step 300
300
#A6C2EE
oklch(80.9% 0.07 259.3)
-
Step 400
400
#76A2E5
oklch(70.8% 0.11 258.6)
-
Step 500
500
#5189DE
oklch(63.1% 0.142 258.5)
-
Step 600
600 (this color)
#3975D0
oklch(57% 0.154 258.7)
-
Step 700
700
#275EB0
oklch(49.1% 0.143 258.6)
-
Step 800
800
#224D8E
oklch(42.6% 0.118 258.6)
-
Step 900
900
#214172
oklch(37.8% 0.092 258.7)
-
Step 950
950
#142643
oklch(27% 0.059 259.5)
#3975D0 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) | #487ED3 | 0.030 |
| Deuteranopia (no green cones) | #2B70CE | 0.019 |
| Tritanopia (no blue cones) | #008A98 | 0.120 |
| Achromatopsia (no color) | #767676 | 0.154 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3975D0
#3975D0
oklch(57% 0.154 258.7)
- #9C6D00
#9C6D00
oklch(56.9% 0.118 78.8)
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 #3975D0, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.029
- Royal Blue #4169E1 ΔE 0.043
- Water Blue #0E87CC ΔE 0.052
- Mid Blue #276AB3 ΔE 0.055
- French Blue #436BAD ΔE 0.056
- Cerulean Blue #056EEE ΔE 0.057
- Nice Blue #107AB0 ΔE 0.060
- Flat Blue #3C73A8 ΔE 0.062
Use #3975D0 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.