Color names are arbitrary.
Those from the WWII period conform to names originally used by Erik A. Pilawskij in his book The Aircraft and Markings of the Soviet Air Forces of the Great Patriotic War . Also used together with Dark Green in two-tone green scheme. Also used together with Olive Green in two-tone green schemetroughout the war. Also part of the later Southern Front standard scheme. X214 Dark Sea Grey Part of standard topside scheme for all single-seat fighters from 1944 onwards.