thanks for all the reply, sorry as i jus back from bangkok
yah the skylight filter gives warmer colors, i like using it for some nature or flower shots
i do read some polariser good for shots directed on metallic surfaces!!!
Yes, UV is still acceptable indoors. Very few people buy the NC filters anyway.. Since UV performs the same job.. A good UV filter will not add any colour cast.
UV should be neutral on digital cameras. I think I read somewhere that CCD/CMOS sensors don't pick up UV as much as infra-red.
And UV is NOT blue, it's beyond the visible range.
UV filters were more important in the days of film cos the blue layer in film reacts to UV rays too.