How are you planning to use the 5c? It's still not a bad phone as I have it as my back up phone, but I also don't use it everyday either. If you're simply going to use it for basic tasks like email, call, text, social media, streaming music, you'll probably be fine. But if you're going to be playing games on it, you may want to at least look at the 5s. Also, if you're looking to purchase it brand new, they only sell it in 8GB variety so if you plan on downloading a lot of apps to your phone, space will be an issue at some point in time. If you're looking to buy used, you can easily find more storage capacity (16GB, 32GB).
As for what color is best? That's ultimately your decision, not ours.
I have a 5C as a company phone and I have a 6plus for personal use. I think 5C is a great phone if you get it as free phone with your plan. It's more portable, easier to talk and I do find it better than 5 in performance wise (I had a 5 for 2 year before 6plus). but honestly I won't get it if I were have to spend any money.
My dad has a 5c. I think it's a great phone. Would I buy one now? No, not this late in the cycle. Wait a few months for the 6s to launch and all the phones to be shifted down a notch and you will get a more recent phone for 5c money. Which colour? Whichever you like best - surely?
Why would anyone ask what color is best from strangers that have their own preference ? Pick your own color. iPhone 5c is OK, but many would opt for the iPhone 5s instead=Better all around. Wait until iPhone 6S comes out for a good price on the 5c