#3370C5
Closest named color: Windows Blue (#3778BF). oklch(54.9% 0.147 257.4), rgb(51, 112, 197).
Aa
White text reads best on this color (4.92:1).
About this color
#3370C5 is a medium-dark, vivid blue. In OKLCH its lightness is 55%, its chroma 0.147 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.026 away. White text reads best on it, at 4.92:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | vivid (0.147) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.26:1 |
| White text | 4.92:1 |
Values
| HEX | #3370C5 |
| RGB | rgb(51, 112, 197) |
| HSL | hsl(215, 59%, 49%) |
| OKLCH | oklch(54.9% 0.147 257.4) |
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 #3370C5 | 4.92:1 | AA | Lc -79.2 | Fine for body text |
| Black text on #3370C5 | 4.26:1 | AA large text | Lc 30.3 | Non-text elements, placeholder text |
| #3370C5 text on white | 4.92:1 | AA | Lc 73.7 | Content text, not long reading |
| #3370C5 text on black | 4.26:1 | AA large text | Lc -28.0 | 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 600.
-
Step 50
50
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EBF7
oklch(93.7% 0.019 255.5)
-
Step 200
200
#CADBF2
oklch(88.6% 0.037 256)
-
Step 300
300
#A6C3EC
oklch(81% 0.066 257)
-
Step 400
400
#76A2E2
oklch(70.6% 0.106 257.7)
-
Step 500
500
#528ADA
oklch(63.2% 0.135 257.4)
-
Step 600
600 (this color)
#3370C5
oklch(54.9% 0.147 257.4)
-
Step 700
700
#275FAC
oklch(49% 0.136 257.3)
-
Step 800
800
#224E8B
oklch(42.7% 0.112 257.3)
-
Step 900
900
#21416F
oklch(37.6% 0.088 257.6)
-
Step 950
950
#142741
oklch(27.1% 0.055 256.6)
#3370C5 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) | #4678C8 | 0.030 |
| Deuteranopia (no green cones) | #2B6AC3 | 0.019 |
| Tritanopia (no blue cones) | #008491 | 0.114 |
| Achromatopsia (no color) | #707070 | 0.147 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3370C5
#3370C5
oklch(54.9% 0.147 257.4)
- #966700
#966700
oklch(54.9% 0.115 77.4)
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 #3370C5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.026
- Mid Blue #276AB3 ΔE 0.033
- French Blue #436BAD ΔE 0.039
- Flat Blue #3C73A8 ΔE 0.048
- Nice Blue #107AB0 ΔE 0.050
- Royal Blue #4169E1 ΔE 0.050
- Muted Blue #3B719F ΔE 0.061
- Water Blue #0E87CC ΔE 0.062
Use #3370C5 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.