Have ds 14 weeks old has been a little hungrier lately, but he can be colicky occassionally and windy. I want to switch to a heavier formula he is on Aptamil Blue, do I switch to the purple Aptamil Extra for hungrier babies or because he is colicky do I switch to Yellow Aptamil which is gentler formula but still for hungrier babies. Anyone tried either and can shed some light on the situation for me. Cheers