Excel (VBS): Colour/Color Palette

I'm not sure if this is a bit left field, but we did touch on colour properties on both VBA courses.

I produce spreadsheet tools for dissemination. I use a color palette recommended for visual imparement. In the majority of cases this works fine. But I notice that a different colour scheme displays on a few machines. I assume that the palatte has reverted to Excel standard.

Is there a simple line of code to 'lock in' a modified color palette to a spreadsheet that will be used on multiple machines? Or should I define the whole palette (or, at least, the colours that need to be different from the standard palette) in VBA?

Cheers,

S!