If its only slight color blindness you might be able to pass class one medical, As far as I know once you can determine Green from red you can pass. Don't hold me to that would have to ask someone like a pilot.
Sorry about the mistake there! you're applying to engineering. Don't know wether you saw it or not Aer Lingus were looking for appertenices I applied and waiting to hear something back, Just as many options engineering wise! again aptitude test stand in the way but lots of options once you Finish your degree.
Lufthansa seem like a good option if you can get it so definitely apply.
Best regards
Philip