I've got a Z3 Compact (D5803) running stock 4.4.4 and Walkman App (8.5.A.3.2) with a DragonFly 1.2 and it changes colors properly with all 4 sample rates, 44kHz:green, 48kHz:blue, 88kHz:amber, 96kHz:magenta so it doesn't do any resampling. I normally use UAPP with the DF because there's no volume control when using the Walkman App.
Even though 5.0.2 is available for OTA flashing now, I chose to stay with 4.4.4 because of various unresolved issues with 5.0.2 on the Z3/Z3c. Now you've documented another reason for me not to upgrade. I think I'll wait until the 5.1 release is ready and see how that goes for others before I decide if I want to "upgrade". The phone works great for me as it currently stands now that I've figured out how to fix the AptX bluetooth music streaming stuttering issue.