2021 Tromba Competition

Last year was a bad year for growing trombos, for me anyway, I just didn't get the heat that I think they need, so this year the area I will will be growing them where they will get full sun, when it's out, but it will also get a cold wind, so I intend putting up a protective polythene screen behind the climbing net, that they will hopefully climb up, the question is should I put the black or the white side to the plant, or would I be better using clear polythene as a screen?