Table: us_house_2006_elections_7
Columns: district
incumbent
party
first_elected
results

Question: Who is the incumbent for the Colorado 4 district?
SQL: SELECT "incumbent" FROM us_house_2006_elections_7 WHERE "district" = 'colorado 4'

Question: What district is the incumbent Republican and the incumbent retired to run for governor democratic gain?
SQL: SELECT "district" FROM us_house_2006_elections_7 WHERE "party" = 'republican' AND "results" = 'retired to run for governor democratic gain'

Question: In Colorado 6 district what is the party?
SQL: SELECT "party" FROM us_house_2006_elections_7 WHERE "district" = 'colorado 6'