I just painted a panzer III with RAL7028 and want to know if i can use a light color filter to lighten up the base.

I suppose you could. I don't use filters (not even sure what they are). To lighten up the base coat, I just spray on a lighter shade of the base coat. So, you're using Dark Yellow. Lighten it up with 10-20% white and spray in the center of panels, leaving the outer edges alone.

I just read that you can not lighten the base with a filter. You can only darken it. I will try your suggestion. Thanks. Bob

After your base coats of paint, you need to seal with gloss, then decal, then seal with gloss again. Now you add your filters. Each filter coat just slightly darkens the base color from the effects of nature. It's not meant to change the base coat color.

If you want to lighten, darken, or change colors, including fading/bleaching, you apply more paint to those selective areas.

Two entirely different applications.
Joel

Hi Bob
You can lighten up colors with a particular type of filters.

see this topic :

https://armorama.kitmaker.net/forums/203868&page=1#1707895