i do the same with my underwear a new pair every day just like david beckham does
i used to wear boxers no longer since i think they hide too much of the legs and the glutes dont look as good in them so now i only wear tight briefs
i would recommend white over black as they give a fresher sexier look especially if you got a mad tan going on occasionally i mix it up and throw a unexpected colour in their like camo or baby blue or even orange works really well with a good tan in the summer