Computes the contrast ratio between foreground and background colors as
defined by WCAG 2.1. Ratios range from 1 (no contrast) to 21
(black on white). WCAG requires at least 4.5 for normal text (level AA),
3.0 for large text (AA), and 7.0 for normal text at level AAA.
Usage
ekio_contrast(color, background = "white")
Arguments
- color
Character. Foreground color(s) as hex codes or R color names.
- background
Character. Background color(s) (default: "white").
Recycled against color if needed.
Value
Numeric vector of contrast ratios between 1 and 21
Examples
ekio_contrast("black", "white")
#> [1] 21
ekio_contrast(ekio_pal("blue")["700"])
#> [1] 11.50262
ekio_contrast("white", ekio_pal("blue"))
#> [1] 1.101930 1.502798 2.125206 3.141442 4.781517 7.482243 11.502620
#> [8] 14.517373 17.393901
