You'll struggle to find any accurate confirmation, as all the photos are black and white, and not much is written about the later units, which existed only briefly.
Troops wore khaki as a starting point. Photos of the colourful units show few in black shirts at any time (and the Alexievs wort khaki blouses as standard anyway – the RCW Osprey is wrong that they wore white shirts).
They would then, as circumstances permitted, try to obtain "colourful" bits.
Shoulderboards in the correct colour (light blue for Alexievs) didn't take much doing, although the insignia would often be written on, not nicely stencilled.
A coloured cap band again only requires a simple strip of fabric and a few minutes sewing to put it onto a normal cap.
Finding a white peakless cap was not a simple matter however. Where are you going to find a brigade's worth of white caps in wartime? (A unit might get lucky though, and I know one example of a Drozdovsky cavalry unit managing in mid-1919. They may have dyed the cap red and added a white band. Some units resorted to paint IIRC to achieve the same effect.)
Sewing piping onto your cuffs doesn't seem very likely for battledress. Especially for impressed ex-Reds who might lose their life if captured with such hard to remove details.
YMMV, but khaki dress with blue shoulderboards and cap bands is at least feasible. With some officers maybe in the full white cap and cuff lace.