I've made some tests with other configuration than Outlook <-> Android.
So I tried the Thunderbird sync, on a factory reset tablet.
First of all, I didn't get the photos though they are synced in Thunderbird (from a CardDav server). I think that contact categories weren't there neither ?
Tasks and events didn't get the categories synced and not the color of the event.
Both are synced when source is outlook and not TBird.
Is there anything that I could modify in the parameters so that I get all this sync ?
Is there an access that you can have to the colors<->category matching in lightnng so that you can sync the colors (as per-event color) to the android device