If you have greenery, such as the plants and bushes outdoors, or a green Christmas tree, you should use green wire lights on them, not white. And vice-versa. it's like an unwritten rule. It doesn't look good to place white wire lights on greenery. And if you have artificial trees in various other colors, that is cool, and a seperate issue, but they should have come pre-lit with the same color wire lights as the tree itself is. Thank you for cooperating from everyone else who has to look at it done wrong.
But don't get me started on pre-lit trees. Buy them with no lights on them, add your own. Save the hassle in the years to come. Trust me.