Ohh, really great idea! I'll try to this daily, let's see if I can keep up
Day 01: A song you like with a colour in the title
I have to go with
GREEN, it's so unique sound-wise and also it was the first single of hers I got to see being released (I knew ayu a bit after MW came out), so I still remember teasers, seeing the covers being released, being amazed at how gorgeous the PV was. Plus I really love the lyrics!