Amber (#FFBF00) is a light, highly saturated orange hue. Amber sits between yellow and orange, named after fossilised tree resin; it is the standard colour for caution lights.
In RGB it is made of 255 red, 191 green and 0 blue. Its HSL hue angle is 45° with 100% saturation and 50% lightness, while its perceptual OKLCH lightness is 84% with a chroma of 0.172. For print, a starting CMYK mix is 0% cyan, 25% magenta, 100% yellow and 0% black.
As a text color on white, Amber has a contrast ratio of 1.65:1, which fails WCAG AA even for large text. On black it reaches 12.7:1 and passes AA for normal text. If you use Amber as a background, put black (or very dark) text on it. The APCA lightness contrast is Lc 75 for black text and Lc -32 for white text.
Its perceptual complement is #B1CBFF, close to periwinkle. Colors that look most similar are gold, orange, mustard. It looks fairly similar to people with red-green color blindness (ΔE 5), so its meaning mostly survives.