UV and Haze filters are similar, if not the same, and are neutral in color. They're meant to reduce UV (naturally), which improves the look of distant landscapes, among other things. You can leave them on all the time.
Skylight filters are pale pink, or salmon-colored, and are warming filters, meant for use in open shade, where most of the light is coming from the sky, which can give a blue cast to your picture. If you use them indoors, or in bright sunshine, white areas can look pinkish. To see the color of a skylight filter, put it on a white piece of paper, and it should be obvious. Pat White
