Male MC returns in the first chapter to his old old town to attend a friend's funeral (I think) and reunites with another friend there (a girl of similar age).

First chapter was colored, or had a number of colored pages.

Colors looked like very soft water color. Maybe. Definitely soft, but not necessarily water.

Looked like a romance/tragedy.

Was set in the summer, I think. Had a lot of soft blue backgrounds. The MC and his friend met near the shore, on a bridge or a walkway near the water.

Summer Time Rendering?

It wasn't Summer Time Rendering.

I don't think it was Sci-Fi. But it may have had some very subtle supernatural elements (or none).

Focus was on romance/drama (mostly), not mystery/action like in Summer Time Rendering.