The Spanish word 'rojo' meaning 'red' comes from the Latin word 'russus', which meant 'deep red'. This is a straightforward evolution where the Latin word simplified in both form and meaning to become the modern Spanish term for the color red.

The word 'rojo' is one of the basic color terms in Spanish, and as such is already among the simplest and most fundamental vocabulary words. You'll encounter it very early in your Spanish learning journey.

While 'rojo' itself doesn't have many obvious English cognates, the related Latin root has given English some interesting color-related words. The word 'russet', meaning a reddish-brown color, comes from the same Latin source. This connection can be seen in terms like 'russet potatoes', which are named for their reddish-brown skin. The word 'rouge', borrowed from French but ultimately from the same Latin root, is another English relative meaning a red cosmetic or the color red.