#645DDC
Closest named color: Dark Periwinkle (#665FD1). oklch(55.5% 0.188 280.8), rgb(100, 93, 220).
Aa
White text reads best on this color (5.07:1).
About this color
#645DDC is a medium-dark, vivid purple. In OKLCH its lightness is 55%, its chroma 0.188 and its hue 281°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.018 away. White text reads best on it, at 5.07:1.
| Hue family | Purples |
| Lightness | medium-dark (55%) |
| Chroma | vivid (0.188) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.14:1 |
| White text | 5.07:1 |
Values
| HEX | #645DDC |
| RGB | rgb(100, 93, 220) |
| HSL | hsl(243, 64%, 61%) |
| OKLCH | oklch(55.5% 0.188 280.8) |
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 #645DDC | 5.07:1 | AA | Lc -80.0 | Fine for body text |
| Black text on #645DDC | 4.14:1 | AA large text | Lc 29.4 | Dividers and decoration only |
| #645DDC text on white | 5.07:1 | AA | Lc 74.6 | Content text, not long reading |
| #645DDC text on black | 4.14:1 | AA large text | Lc -27.1 | 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
#F4F5FD
oklch(97.2% 0.011 280.5)
-
Step 100
100
#E6E8FA
oklch(93.5% 0.024 280.9)
-
Step 200
200
#D3D6F8
oklch(88.5% 0.047 281.4)
-
Step 300
300
#B6BBF7
oklch(80.9% 0.085 280.6)
-
Step 400
400
#9295F3
oklch(70.7% 0.136 280.9)
-
Step 500
500
#7978EE
oklch(63.1% 0.173 280.6)
-
Step 600
600 (this color)
#645DDC
oklch(55.5% 0.188 280.8)
-
Step 700
700
#544CBF
oklch(49.1% 0.174 281)
-
Step 800
800
#443F9B
oklch(42.7% 0.145 280.7)
-
Step 900
900
#39377B
oklch(37.8% 0.112 280.9)
-
Step 950
950
#212148
oklch(27.1% 0.071 280.6)
#645DDC 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) | #0073E0 | 0.084 |
| Deuteranopia (no green cones) | #006AD9 | 0.080 |
| Tritanopia (no blue cones) | #2A7B93 | 0.162 |
| Achromatopsia (no color) | #6E6E6E | 0.189 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #645DDC
#645DDC
oklch(55.5% 0.188 280.8)
- #827400
#827400
oklch(55.5% 0.116 101)
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 #645DDC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.018
- Light Indigo #6D5ACF ΔE 0.024
- Slate Blue #6A5ACD ΔE 0.025
- Iris #6258C4 ΔE 0.038
- Warm Blue #4B57DB ΔE 0.039
- Royal Blue #4169E1 ΔE 0.047
- Neon Blue #4361EE ΔE 0.049
- Medium Slate Blue #7B68EE ΔE 0.052
Use #645DDC 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.