Shaded Elevations - how to achieve pure white? How to achieve solid+transparent areas within fills?

[Paul King]

Hi, just wondering how people are getting white painted elements in shaded elevations to appear white, rather than grey? I cannot seem to find any surface definition characteristics that result in this outcome.

Also, has anyone come up with a cunning way that a cover fill for a perforated wall panel element can have a pattern of white masking areas alternating with transparent hole areas that are individually outlined with black pen? (as opposed to the outline of the fill as a whole)?
I can achieve this in 3D with alpha channel for transparency in surface texture, but cannot think of a way in 2D.

Really hoping to avoid physically modeling every perforation to achieve this, as there are thousands of holes, which will massively slow down the model.

[Lingwisyer]

If you use CUTPLANE then everything on the set side of the plane will be removed. This plane can then be manipulated with your standard transformations.