It is the same dilemma that I have had.
I have not yet been contacted by any important client, but it has been on my mind ever since I decided I wanted to do photography as a profession.
Many times I wondered if staying with my artistic decision to do BW would be naive in the broad professional world and I would just end up starving and kicking myself for being such a fool.
But then, if I did just what everyone else does, color and in digital and whatever the client asked for, then what would be the difference of any cheap whore with a digicam that calls themselves a photographer? Putting artistic and personnal matters aside, what would be the reason to get a job then, if anyone else can do it? Wouldn't my name and my professional status dissapear in a sea of identical clones?
Practically, would I make any money, or would I just end up working for an one hour shop in cliche weddings and crowded events for spare change?

Would that decision, to sell my artistic vision out, lead me anywhere? Would I have a career and a future or be a beggar clone with really nothing to look for?

Someome who makes the decision to stand aside from the crowd has always a rough beginning. But atleast has some chance for an interesting life and career.

So, in the end, better to be a fool full of dreams and passion than an empty clone.

There always going to be people who don't understand and ask you to change your artistic work to suit their shallow and ignorant fancies. Don't let them destroy you.