Light blue and light red are happening slowly, darker blue and darker red are happeningly rapidly. In some cases the trend is irrelevant to the electoral college because the state is trending in the direction of its current orientation, though this is mostly true in Republican-trending states.
There are also degrees of trend; Indiana and Montana are slightly trending Democratic, but not nearly so much so as Nevada, which nonetheless is not even comparable to Virginia or Colorado or New Hampshire.
Overall, the trend of increasingly-populous Republican states combined with the slow trend of borderline states to the Democrats continues.