Hello,
i had the same issue :)
the issue seems to be with gtk-3 based apps. The widgets dont have any decoration, like input fields have no visible borders, check boxes no borders.. menu controls have only their text / titles drawn without any space and border in between their characters... I tried to post a mail here but after a few days i understood that this list silently drops mails with attachments...
Examples of apps affected i used were Evolution (completely unusable with this behavior) and Synaptic (i switched to aptitude for package management).
i recovered the screenshots from the sent folder and put them onto imagebin:
https://imagebin.ca/v/2jsCHryiFpi8https://imagebin.ca/v/2jsEiMInvzRD https://imagebin.ca/v/2jsEw627EVgh I purged my home directory completely to get rid of all . directories with eventually wrong config files, created a new user account to check as well.