To be clear, this decision is based only on the fact that this is a primary election in which the courts have no jurisdiction to prevent parties from nominating a candidate. It does not stand for the proposition that Trump didn't engage in an insurrection, or that he cannot be barred from the general election ballot.
Trump actually is very fortunate that the Colorado court did what it did, because it gives him a chance to challenge directly in the Supreme Court the merits of the insurrection argument comparatively early in the election cycle.