Re: [PATCH 0/1] MR6547: uxtheme: Better detect the presence of default transparent colour in prepare_alpha().

[Paul Gofman (＠gofman)]

Fixes a regression described here: https://gitlab.winehq.org/wine/wine/-/merge_requests/6401#note_82961 (where the theme has 8 bit paletted bitmap with default transparent colour which was displayed as pink instead of being transparent after the blamed commit).