Need help environmental lighting

How would one make blue environmental lighting from red and blue environmental lighting? I don’t know where to go, or what to do… carcols or carvariations?

If your lights are red & blue and you want them to be blue, you must change the texture colour in the ytd, then change the colour hex in the carcols.meta, make sure the carvariations.meta for the vehicle is pointing to the correct sirenid corresponding with the chosen sirenid for that specific vehicle in the carcols.meta