Play again & Ball on after the foul

[catania]

The player who committed the foul(not miss) is requested to play the next stroke .
His last (unsuccesful) stroke was on colour after potting a Red.
What can be his the 'ball on' in the next stroke?
Is it red because he start his new turn?
Is it colour because he 'plays again' and the foul was commited when playing on colour?
Or He can choose?
Thanks for the answer

[jrc750]

Yes it's a red he has to go for