The first rule of wargaming markers is that when you go to get the ones you need you find that you either have far too many or not quite enough. Notwithstanding the fact that we have played C&C several times and that line infantry are always A, that's the letter of which I was short; which is why I have been making some more; current status second coat of PVA drying. The last time we played I didn't have enough 3s.
I have also been pondering the look of the thing. It seems to me - and I've never discussed it with him - that in making markers James goes for invisibility at a distance (a). In other words, close-to the markers clearly indicate whatever they are meant to, but when one stands back they rather blend in to the background of tabletop and figures, becoming inconspicuous. I went down a similar route myself when making casualty markers for 'Through the Mud and the Blood' and for 'To the Strongest!' early Imperial Romans and Celt. However, I think for C&C the opposite is more appropriate. While the look of the original boardgame is improved by playing with figures, the whole aesthetic is nonetheless the opposite of naturalistic. There is no attempt to deny its roots in cardboard map tiles and wooden blocks; rather the contents of the box are simply replaced with better looking (and, by the way, better to handle) surrogates. In my view the very obtrusiveness of the markers acts to reinforce that rather tahn pretend to be something it's not.
(a) the exception to this are the markers for ancient galley warfare - grappled, fouled, raked etc - which are very distinctive.