"Her dress is purple."
Translation:Její šaty jsou fialové.
Well, yes and no. In English "purple" is a generic word for any combination of red and blue. It comes in many shades but for many people it is just "purple". In Czech that word is "fialová". It is any combo of red and blue. English has violet and maroon, fuchsia, magenta.... Czech has šeříková, purpurová, bordó but generally it is fialová. Since everything needs to be edited manually teaching shades of colors does not seem to make the top of the urgent list.