What uynderwear with white linen trousers?

[YouMightKnowMe]

title says it all....and none is not an option.

Do I go white?
Skin tone?

Normal briefs or do I have to go for a thong?

Nude ones. And for the love of god make sure they actually fit. I lost count of the number of wobbly dimpled arses in too tight white linen today and it put me off my 99 good and proper.