I read this manga few months ago when my HDD broken and I lost the scanlations.

The story is about a guy who works in a shop, I am not sure what kind of shop (not Yamamoto Kotetsuko's manga). There is this younger guy who become a part timer on the shop and then their relationship progressing slowly, with some angst and argument. What I remember is that the older guy lived on the top of the shop. If I'm not mistaken, the title related with month or color.

If somebody notice the manga that I mentioned, I would be really grateful.

Thank you.