Epoxy with white pigment
I used epoxy (no thinner) with white epoxy pigment - West 501. This was following a suggestion by Bruce Hill.
I couldn't find any instructions for this pigment but you definitely need to work up from very tiny amounts (less than a small pea in a one-pump-stroke mix). The mix turns solid white with very little pigment and adding more will actually make the mix turn 'gloopy'. I added some cabosil to make sure it did not run on the sides of the cowl.
I put it on with a squeegee and then rolled it with a foam roller - like the pin hole filling method. 3 coats filled much of the weave and left a shiny surface with little 'goose bumps' from the roller. I will probably sand those out - at least where the adhesive foil is going.
The white epoxy does not give the same color coverage as paint. If you want totally uniform solid color, paint will be needed. However, you should probably seal with epoxy anyway so why not add the pigment.