They are usually in a two tone gray TPS pattern

http://www.jpsmodell.de/dc/main_e.htm

after you click on the link, click through the index on the left under camoflages to find the AH-1 pattern in use since 91.

Try this, got it from another builder for my build

/forums/2/1109438/ShowPost.aspx#1109438

I was about to re-post the link ...

Anyhow it's a two color gray scheme: Light gray (FS-36375) and Blue Gray (FS-35237)