At the congressional seat level there really wasn't a way that they could 'safely' force a 4-3 or 5-2 set of congressional districts. They could force a 3 safe Dem seat 2 safe republican seat and 2 competitive districts that pitted 2 incumbent Republicans against each other. Lest anyone forget Colorado was for a couple decades a solidly 4-2 5-2 Republican house majority even while Democrats controlled the statehouse due to the differences in redistricting at the state level. 

But this is nothing new.  Anyone with a half a brain could tell that Colorado's legislative districts have been gerrymandered by the Democrats either in the legislature or through the courts (more recently always the courts) for the past 40+ years.