Ok, so as promised lens tutorial. This is the easy way and I think I did it too fast. I will have to fix something that doesn't look right, maybe the angle but still the idea is the same. Start with black.then apply yellow to the lower left or right side doing a maybe 45 or 60 angle. try to keep it neat so that it looks more reflective.
Apply gnarloc green to either the lower or upper side depending on whether you like it to look more yellow or green.
Put a big white dot on top and with the white very diluted draw a line on the opposite side of the dot. Like drawing the lower part of the circle, no need to be neat there. Since this detail is so small it looks very cool looking at it with your own eyes, the photography shows the mistakes but still looks good I think :)
Hope you guys enjoyed this little tutorial :D