Merge pull request #26646 from nullaus/bug1100842

bug 1100842 - Use solid color for dialog background like all other dialo...
(cherry picked from commit 1d9ae9cca415ad093beba9521c429350e1f2b14d)
Merge pull request #26797 from nullaus/v2.1

Merge pull request #26646 from nullaus/bug1100842