Question: Who is the incumbent for the Colorado 4 district?
SQL: SELECT "Incumbent" FROM "2-1805191-7" 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 "2-1805191-7" 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 "2-1805191-7" WHERE "District" = 'Colorado 6';