I’ve noticed some styles in Millau is overwriting the configuration in the theme builder for our custom theme.
E.g.
/* Drawer */ table.nx-skootable-data tbody tr.nx-item-has-drawer td, table.nx-skootable-data tbody tr td.nx-item-drawer { background: #F3F2F2; }``` The background color in my custom theme is overwritten by the above. It seems that custom theme has no effect at all. It worked fine in Rockaway and Brooklyn.
My first thought would be to check if the drawer has a page include. If so, the page include’s theme should be set to the same theme as the parent page. Also, a more basic suggestion - always ensure that they’ve run the “Update out of date themes” process on the themes page.
Looking at your original example, I wanted to make sure - do you have a custom background color set up for your drawers in this custom theme? Or, does the missing background color refer to the page or table’s main background color?
Also, are you working in Lightning? If so, does the issue happen both in Lightning and classic Salesforce?