- Add safeguards for invalid idx when opening color picker
- Prevent crash when filament color data is missing or uninitialized
- Simplify private member variable naming in filament picker dialog
jira: STUDIO-12956
Change-Id: I455565bdac769f497f22f884e19cd0cbb04fb8c3
(cherry picked from commit 705ad911ee81395b2162ae67a8f64e237f6a3c5d)