Skype fail

I was recently asked to have a conversation with someone on Skype.
It seemed a reasonable request, although I have seldom used Skype.
The caller sent me a chat message, then initiated the call. Skype uses similar icons in red and green, side by side, to initiate a call and terminate it:

Skype phone

I clicked on the wrong one, so embarrassingly killed the call. On the second attempt I clicked the other icon and we had our conversation.
Once again I see no need for these colours to be used, so come on Skype make sure that you have colourblind usability testers. I'm available for a large fee.