I’ve not used the Acrylics on a helmet yet. But the Enamels I used are as follows.
ESB Helmet
Dome and lower cheeks Light Green and Grime 50:50ish, tape pull was same but with more Grime. SP Dark Lark for main grey and greenish grey parts SP Lettering Grey
Visor/Mandible/Keyslots D&H Caboose, SP Dark Lark, Maroon mixed 50:50 Engine Black. Greenish grey parts done with SP Lettering Grey.
Upper Cheeks were painted D&H Caboose first then Grimy Black. Grey is SP Dark Lark.
Right Ear Earth Lt, SP Dark Lark, Engine Black and Tamiya White Primer
Left Ear Coach Green first, then Light Green. Lighter grey is ANH DS Surface Grey and Red is Caboose. Spatter is Rust. White for decal/graphic is Tamiya primer.
Killstripes SP Armour Yellow with gradient to Mixture of SP Armour Yellow and Rust.
Rear panels main green is Engine Black and Dark Green 50:50. Then Dark Grime, SP Dark Lark and SP Lettering Grey for greenish grey parts.