The changes made to the level's Color overrides are not being saved permanently or for an extended period of time.

Here is another article that also addresses a couple of settings that apply if these are reference levels (specifically SET REFLEVELOVERRIDES): communities.bentley.com/.../overriding-and-resynchronizing-level-attributes

Here is another article that also addresses a couple of settings that apply if these are reference levels (specifically SET REFLEVELOVERRIDES): communities.bentley.com/.../overriding-and-resynchronizing-level-attributes