Do my photos' colours change when I upload them?

They should not look different after upload: you do not need to convert anything first. Panoramr shows every panorama in sRGB, the colour space browsers and phone screens expect, and a photo saved in a wider colour space, such as Adobe RGB from Lightroom or a camera, or Display P3 from an iPhone, is converted to sRGB as the tour's pictures are made, so its colours look the way the photo meant on every screen.

There is nothing to switch on in the editor: the conversion is made once, for every new panorama, however the photo comes in. Photo colours: Adobe RGB and Display P3 says which photos are converted and what to check when colours still look wrong.