Scarlet (#FF2400) is a medium, highly saturated red hue. Scarlet tilts toward orange and was historically one of the most expensive dyes, worn by cardinals and military officers.
In RGB it is made of 255 red, 36 green and 0 blue. Its HSL hue angle is 8° with 100% saturation and 50% lightness, while its perceptual OKLCH lightness is 64% with a chroma of 0.248. For print, a starting CMYK mix is 0% cyan, 86% magenta, 100% yellow and 0% black.
As a text color on white, Scarlet has a contrast ratio of 3.82:1, which passes AA only for large text and UI parts. On black it reaches 5.5:1 and passes AA for normal text. If you use Scarlet as a background, put black (or very dark) text on it. The APCA lightness contrast is Lc 41 for black text and Lc -69 for white text.
Its perceptual complement is #009DB1, close to dental teal. Colors that look most similar are red, crimson, raspberry. People with red-green color blindness see scarlet quite differently (ΔE 24), so do not rely on it alone to signal meaning.