исправьте ошибки, пожалуйста!

1.All his landscape paintings are true-to-life, though he painted them by memory.
2.Gainsborough portrayed Sarah Siddons in background of the red cloth.
3.This painter was distinguished by marvelous sense of composition.
4.The mature artist selected a wonderful colour scheme to render emotions by moving sincerity.
5.The artist was in advance with his time.
6.The artist,specialized in portraiture developed his own style of painting and once became famous overnight owning to his unsurpassed masterpieces.
7.The majority of talanted artists are self-taught.

ошибки могут быть не только грамматическими.

зарание спасибо!