Almost all Bf109 K4 were build from the Messerschmitt factory ion Regensburg (block 330xxx) some few were produced from the Erla factory (block 570xxx) but it is still very few kown about the Erla build K4 camouflage.
The early Regensburg Bf 109K4s wore similar camouflage to the Regensburg build Bf109 G14/AS.
In later camouflage versions with RLM 76/02/83/81 the engine was painted with RLM 77 - there are two variations.
V2: Skins with alpha layer added V3: Corrected some glitches with stencils