If it's a roman temple. I wouldn't make the pillars brown. White is probably the way to go.
I think he's going for a 'fallen' temple. One that hasn't been renovated over the years. Hence the bricks and ruin blocks. Those temples don't have white pillars anymore, either.
Roman tempels that big are usually way longer. If you're going for realism, I would go with a litter tint of brown. Close to that of the walls.
I do think you actually have too much brick going on for a roman temple. Especially the brick walls around the pillars and statues.
If it's a roman temple. I wouldn't make the pillars brown. White is probably the way to go.
im too lazy to look it up but there's an exact ratio they used for every temple
EDIT: the long side of a temple has twice as many pillars as the shorter side, with one extra. so if x is the short side, the long side is 2x+1