Here's my 2 cents:

Worked around simple & green if you like.

ColX Logo: https://drive.google.com/open?id=0B-Elfxo1gHZ8cGM4ZmVJRGd1Nms

ColX Icon/Coin: https://drive.google.com/open?id=0B-Elfxo1gHZ8RmlQLTVPZzV1eXM

ColX Logo Alternative - with tree rings (growth symbolization): https://drive.google.com/open?id=0B-Elfxo1gHZ8RzhuMnpaWUJJbkk

Colx Icon on Gray Background (only for test): https://drive.google.com/open?id=0B-Elfxo1gHZ8aVBiek1OWHRBWHc

Good luck everyone!

Great contest