The percentages describe how much white or black is added, not opacity or a design-system shade number. A 20% tint is 80% base color and 20% white. All results are solid, opaque colors calculated from the encoded sRGB channels.
For each red, green, or blue channel c and mix fraction p, a tint is round(c × (1 - p) + 255 × p); a shade is round(c × (1 - p)). For example, #336699 at 20% white becomes #5c85ad, and at 20% black becomes #29527a.
For a perceptual, numbered interface scale, use Color Shades for Figma. To explore complementary or analogous hues, use the Color Palette Generator. This table focuses on reproducible white and black mixing recipes.