Sort of chart, plain black and white (7)
I believe the answer is:
piebald
'black and white' is the definition.
(I've seen this before)
'sort of chart plain' is the wordplay.
'sort of chart' becomes 'pie'.
'plain' becomes 'bald' (both can mean unadorned).
'pie'+'bald'='PIEBALD'
(Other definitions for piebald that I've seen before include "(Of horse) patched with two colours" , "Motley" , "Two-coloured (horse)" , "Of horse, with patches of white and dark colour" , "Marked in two different colours, especially black and white" .)