The Cook Political Report claims (as of a month ago)that there are 20 seats that are likely or leaning Democratic party seats, and 54 Republican seats that are likely or leaning Republican or are toss ups. Fifteen of those Republicans, and none of the Democrats, are in toss up seats. Every other seat is deemed a safe seat for the party that holds it.
In Colorado, the 7th CD (currently Bob Beauprez) is listed as a toss up, and the 4th CD (currently Marilyn Musgrave) is shown as a likely, but not sure, Republican win. John Salazar's 3rd CD seat is listed as a likely, but not sure, Democratic party win. Salazar's seat has a partisan voting index of R+6, meaning that it tends to vote six percentage points more Republican than the nation as a whole. Musgrave's seat has a partisan voting index of R+9. The 7th CD has a partisan voting index of D+2.
The two regions that are prone to swinging from Republican held seats are the Northeast (14 seats) and the West (Rocky Mountain and Pacific) with 11. The South is mostly bad new for Democrats, but a number of seats in Florida look promising.