#645DF3
Closest named color: Neon Blue (#4361EE). oklch(57.3% 0.217 279.1), rgb(100, 93, 243).
Aa
White text reads best on this color (4.77:1).
About this color
#645DF3 is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.217 and its hue 279°. Its hue sits on the cool side of the wheel. The nearest named color is Neon Blue (#4361EE), ΔE 0.042 away. White text reads best on it, at 4.77:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.217) |
| Temperature | cool |
| Nearest name | Neon Blue (#4361EE) |
| Black text | 4.40:1 |
| White text | 4.77:1 |
Values
| HEX | #645DF3 |
| RGB | rgb(100, 93, 243) |
| HSL | hsl(243, 86%, 66%) |
| OKLCH | oklch(57.3% 0.217 279.1) |
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 #645DF3 | 4.77:1 | AA | Lc -78.0 | Fine for body text |
| Black text on #645DF3 | 4.40:1 | AA large text | Lc 31.5 | Non-text elements, placeholder text |
| #645DF3 text on white | 4.77:1 | AA | Lc 72.6 | Content text, not long reading |
| #645DF3 text on black | 4.40:1 | AA large text | Lc -29.1 | 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
#F3F5FE
oklch(97.1% 0.012 276.1)
-
Step 100
100
#E5E8FD
oklch(93.5% 0.029 279.4)
-
Step 200
200
#D1D6FD
oklch(88.5% 0.054 279.5)
-
Step 300
300
#B3BAFF
oklch(80.8% 0.098 279.5)
-
Step 400
400
#8D94FF
oklch(70.8% 0.155 278.8)
-
Step 500
500
#7474FE
oklch(63.1% 0.2 279)
-
Step 600
600 (this color)
#645DF3
oklch(57.3% 0.217 279.1)
-
Step 700
700
#5046CE
oklch(49.1% 0.202 279.2)
-
Step 800
800
#413BA7
oklch(42.8% 0.167 279.1)
-
Step 900
900
#363484
oklch(37.7% 0.13 279.2)
-
Step 950
950
#1F1F4D
oklch(26.9% 0.083 279.3)
#645DF3 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) | #0079F8 | 0.086 |
| Deuteranopia (no green cones) | #006DF0 | 0.077 |
| Tritanopia (no blue cones) | #00829F | 0.186 |
| Achromatopsia (no color) | #737373 | 0.218 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #645DF3
#645DF3
oklch(57.3% 0.217 279.1)
- #8A7800
#8A7800
oklch(57.2% 0.118 98.7)
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 #645DF3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Neon Blue #4361EE ΔE 0.042
- Medium Slate Blue #7B68EE ΔE 0.046
- Dark Periwinkle #665FD1 ΔE 0.052
- Warm Blue #4B57DB ΔE 0.053
- Royal Blue #4169E1 ΔE 0.055
- Light Indigo #6D5ACF ΔE 0.056
- Slate Blue #6A5ACD ΔE 0.059
- Purpley #8756E4 ΔE 0.061
Use #645DF3 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.