I strongly believe in concentrating on one (or two) areas in photography that you happen to be good at, in stead of trying to achieve a moderate level in all other areas. My favourite (and it happens to be my best area) is landscape photography. What I often notice in Holland is that landscape photographers often combine that passion with potraiture, probably to earn some money. I am not sure why this works, but it does seem to.
As far as colour versus B/W is concerned, I have the same "problem". My B/W is much better than my colour. I guess for me this is because with mono you can be really creative in the darkroom, whereas with colour this is more restricted (unless you go digital........oops this is a swearword here, isn't it...sorry!).