Rebecca Purple

Conversion

The same colour in each notation. OKLCH is the one to reach for when you intend to modify it, because its lightness axis is perceptually uniform and its three components are genuinely independent.

HEX

#663399

RGB

rgb(102 51 153)

OKLCH

oklch(44.0% 0.160 303.4)

Contrast and accessibility

What this colour passes as text, and — where it fails — the nearest colour that would pass while holding the same hue.

APCA scores it Lc 88 as 16px regular text on white. That is below the threshold for body copy at that size, even where the WCAG ratio passes.

Using Rebecca Purple

In OKLCH terms this is a purple at 44% lightness and 0.16 chroma. Lightness is what decides every verdict below, which is why a colour can be perfect as a fill and unusable as the text on top of it.

• Body text on white8.40:1 clears the 4.5:1 minimum.yes
• Body text on black2.49:1 is under the 4.5:1 minimum.no
• Large text or headingsLarge text needs only 3:1, and this reaches 8.40:1 against white.yes
• Borders, icons and controlsClears the 3:1 that WCAG 1.4.11 asks of anything needed to identify a control.yes
• A background for white textWhite on this colour is 8.40:1.yes

None of this makes a design accessible on its own. Contrast is one success criterion among many, and WCAG 1.4.1 separately requires that colour is never the only way information is conveyed — so if Rebecca Purple is carrying meaning here, give it a label or an icon as well.

Closest named colours

Ranked by CIEDE2000 perceptual distance, not by hex proximity. Two hex codes can look almost identical and sit far apart numerically, and the reverse.

• Dark Slate BlueΔE 7.3
• Dark MagentaΔE 9.5
• PurpleΔE 9.6
• IndigoΔE 9.6
• Dark VioletΔE 10.4

Tints and shades

The same hue at eleven lightness steps, spaced evenly in OKLCH so they look evenly spaced. This is the family you would build a design system from.

Colour harmonies

Hue rotations around Rebecca Purple, computed in OKLCH so every colour in a set holds the same perceived lightness — which is what a harmony is supposed to mean and what the same rotation in HSL fails to deliver.

Colour vision

How Rebecca Purple appears under each simulated deficiency, using the Machado model applied to linear RGB.