I'm using the FREEWELL magnetic filters. 5, 10 stops and CPL. It's near 100$ per each. Very handy things! I hate to unscrew "old-fashion" filter just for exposure metering, with magnetic kit it's very easy to do. One bad thing with this kit - you can't add ND Grad to this system because it's always a ring. But I can live with it.
You see color cast on your filter because it is cheap, I guess. I had one ICE 10 stops filter for $20 and it's add so much blue tint on photo that I used it just 1 time.
Good filter must cost much. Last year prices on filters rised even higher.

It's not a cheap filter, just one that for some reason gives me that color cast.












