As nouns the difference between red and reds
is that
red is any of a range of colours having the longest wavelengths, 670 nm, of the visible spectrum; a primary additive colour for transmitted light: the colour obtained by subtracting green and blue from white light using magenta and yellow filters; the colour of blood, ripe strawberries, etc while
reds is plural of lang=en.
As an adjective red
is having red as its color.
As a verb red
is past tense of rede.
As a proper noun Red
is
A nickname given to someone who has or had red hair.