EliodA, the POW with blue or red over-check is a dead-set menswear classic, so there's a lot of precedent re: what works with it and what doesn't.
Seem to be a number of schools of thought on it, which u can really boil down to 2 at either end of the spectrum:
1. The greats of menswear
2. Ed Morel's (err, not mutually exclusive, so no offence Ed)
1. Like Cary Grant here, the best pairings are solid (blue or white) shirt, solid or repp-stripe tie (neat...