[PATCH v2 0/1] MR6547: uxtheme: Better detect the presence of default transparent colour in prepare_alpha().

[Paul Gofman (＠gofman)]

Fixes a regression introduced by
c0bf67636ab3de46c67b8d02e44fb39b5853384a.

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  v2: uxtheme: Better detect the presence of default transparent colour in prepare_alpha().
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6547