I really like the look of seersucker, but I'm color blind. So I don't see reds well, so no purple. The question really is, do I just pick anything, or do I need to match the blue?
I would recommend to never try to match colors unless they are sold together. The colors will never actually quit match and will look off. Just go with something that's obviously a different color. That could also mean the same color, just a way darker or lighter shade of that color.
The picture you posted looks good to me. The stripe color on the shorts is faint anyway, so anything goes.
You don't need to match; you need not to clash. A blue seersucker would look great with this as long as the blue in the seersucker doesn't clash with the blue of the shorts (it probably won't).
Your fit looks good here.
The color saturation of the seersucker is really low and it reads as nearly white. So you've got a lot of leeway when picking colors. I would just steer away from near matching colors and patterns.
To me, colors that almost but don't quite match are the worst. A real pet peeve that drives me nuts.
Seersucker says what?