hi patrick
i haven't used colortek in years to be honest i didn't even know they were still in business!
( i used to go to spectrum, had friends who worked there ... but they are long gone too )
you might look into dorian labs in arlington on i believe it is mill street.
http://www.dorianlab.com
while haven't ever used them, from all reports old ( in the 1990s ) and new
they are the real deal -- a pleasure to work with and do spectacular work.
if you don't have a car, bike, / ride i think it is the arlington bus ( mass ave )
that will let you off on/near the corner of mass ave + mill street or the next street down. ( its near arlington center )
if you get to the chevrolet dealership, blue ribbon bbq, sanford camera and motorcycle shop you have gone to far .
have fun !
john