[kurlannaiskos]

Guards Regiments usually used RED or WHITE for their markings, yellow was not used very much for this kind of thing so it wouldn't be confused with Luftwaffe markings. (they loved yellow)

also the markings were usually painted spinners (red or white instead of camoflage colors)or tips of the fin/rudder.
I've never heard of wingtip markings like this being used by the Soviets.