Pocket square colour when wearing an ecru dinner jacket?

[Ianiceman]

Since my opportunities to wear black tie are almost zero the question is purely academic but I'm watching Robert Redford in 'Havana' where there are a few ecru dinner jackets on display, all sans pocket square. I was just wondering what the convention was for this rig.

In the opening sequence of 'Goldfinger', Connery also had an empty breat pocket but a dashing red carnation boutonnière.

 

[LeviMay]

I've gone with white linen, which is pretty faint and doesn't give much contrast, but this is what Bogey wore in Casablanca, so it's okay in my books. I also once went with a white silk square that had black spots on it. It was fairly matchy with a white shirt and a black bow, but it looked kinda cool.

I think traditionally, this is an opportunity for a little bit of colour, with a maroon or red square being acceptable.