Try to find out why they use blue and not red! Red mean stop, dont but in same time it can take your attention easy, the blue means protection, family care, trust and go ahead... You can see a lot of logos in red theme but maybe they are companies like fast food, in this case red and yellow make the customers to eat fast and go away from your shop! Every color has its usage... Anyway you can do your tests but you have to know that big comoanies have done their tests already and as i am a graphic designer i best colors for your servise is the blue one or green as it gives a feeling about dollars. I hope i helped you a bit.