Hi @andy_t The 90D has not yet gotten proper color support because Adobe Camera Raw hasn’t provided camera-specific DCP files. See Cameras supported by Camera Raw (look for D90, second column says No).
If you have a color target and the possibility to shoot the target under the proper lighting conditions, we could generate a DCP ourselves and include that in RT for a much more accurate color representation. Please see How to create DCP color profiles - RawPedia
Edit: this turned out to be false information. RT nightly builds already ship a good quality DCP profile. Currently it automatically works for DNG’s but needs manual application for CR3’s since metadata support is pending.