The Colorado GOP also released a press release declaring that they will not allow any Colorado delegate to vote for Trump. The Colorado GOP just backed off their tweet because they’re morons. They’re saying the same thing officially already.
That "proposed resolution" didn't come from the party, although perhaps it was presented to the party for consideration. Of course, members of the party, a subgroup, prepared the proposed resolution, and for all I know their sentiment reflects that of a majority of republicans in the state of Colorado. But the state party would never be so overt as to adopt an open resolution against a candidate still in the running - effectively going into open rebellion against the RNC.