Great advice from Drew McLellan’s book 99.3 Random Acts of Marketing:
Next time people want you to change your corporate identity, try this. Buy a can of Coke and place it on their office desk. Give them 30 seconds to study it and then tell them to close their eyes and picture the Coke can in their minds. Then wait a few seconds and ask them to imagine the can of Coke looking exactly the same, except it’s green.
They’ll tell you it’s just wrong. The can has to be red or it isn’t Coke.
That’s your aha! moment. Tell them they can open their eyes and when they do, simply smile at them and say, “And that’s why we don’t change the color of our logo either.”
The whole purpose of your logo and your colors is to build recognition. This takes time. Every time you change it, you start over. Be patient.