| How do you match a paint color on drywall in a bedroom? Cut out of piece
of the wall and take it to the paint store? Is
| there such thing as a portable color analyzer?

A couple of points that haven't been mentioned:

1) When you take the wall sample to the store you'll
also need a store with a talented paint mixer. In
some stores they'll try to discourage you from getting
a computer match because they don't want to be
responsible. Even at a store where they will computer
match, the matching is no miracle, especially with
darker colors. To really get a good match usually
requires that the person mixing the paint be very
experienced.

2) After painting, be sure to save the can, even if
it's empty, so that next time you won't have to go
through all this trouble. It's worthwhile to keep a list
of all paints used. Even if you have to use a different
brand next time. Many companies have formulas for
other companies' paint colors.