We have mobile applications both for iOS and Android. There also is the site, supporting the application. We have put 2 buttons on our site for downloading application. We did like it usually is done: just two grey/black buttons:
And now we are thinking of what if we change the color of the buttons to green, blue or red like we do with CTA buttons. Are there any sense in changing the color? Are there any research done in this topic?
If you want to get featured in the iOS app store, it's best to comply with apple marketing guidelines which require you to use the newest black version of their 'available in the app store' icon that has the apple instead of the phone. They don't usually promote apps that have marketing collateral that goes against their guidance. Google has similar details on displaying their graphic.
Guidelines for google play: http://developer.android.com/distribute/googleplay/promote/brand.html
Apple guidelines: https://developer.apple.com/appstore/resources/marketing/index.html
Too narrow of a subject to have actual research, but, my intuition says you run into the risk of people doubting the authenticity of the link if everywhere they see it as grey and your's is the only one with a different color.
But, like I said, it is a possible risk. If you change the color to match your theme of the website or something you might be able to reduce the chances of that.
