Michael Bennet (D-CO) is running for governor of Colorado. Even if he resigns his Senate seat to run or resigns because he wins, it should not change that the seat will stay blue.
As for the seat up for election, I think Hickenlooper (D) will win handedly. The only other person to declare is also a Democrat and many suspect she is running to either build a war chest or maybe replace Bennet.
tl;dr Colorado seats after 2026 election are still blue & blue.