I suppose you could say that, although the spelling is different and you can leave out the "medi" completely:
o·cher or o·chre (?'k?r) Pronunciation Key
n.
Any of several earthy mineral oxides of iron occurring in yellow, brown, or red and used as pigments.
A moderate orange yellow, from moderate or deep orange to moderate or strong yellow.
drawn in 43 min
o·cher or o·chre (?'k?r) Pronunciation Key
n.
Any of several earthy mineral oxides of iron occurring in yellow, brown, or red and used as pigments.
A moderate orange yellow, from moderate or deep orange to moderate or strong yellow.
Nothing he paints is "medi"ocre.