Any clue as to what this song is? Suiro.mid

I was re-looking at the beta OrgViews I downloaded from the beta music page since it's been a while since I had, and I noticed three midis that I hadn't played before. I downloaded a midi player, and for the first two I got pretty expected things, mizu.mid is the Ikachan title screen, naki.mid is Toroko's theme, but then the other, Suiro.mid wasn't anything I recognized. I looked it up and, apparently, Suiro is Japanese for Waterway, but the song sounded completely different from Living Waterway, even from the earliest beta. Does anyone have any more information about it, or is it just kinda...there? The only thing I found was that Pixel mentioned it on the now archived BBS but that's it.

Links for convenience:
Folder containing Beta OrgViews & Midis: http://doukutsu.rdy.jp/stored/OrgView.zip
BBS Archive where mentioned (@4th August 2011 23:52): http://www.cavestory.org/game-info/bbs-2011-08.php
And I guess a midi player: http://www.gamesbyscott.com/midijam.htm is the one I used.

 

It was probably unused. My guess is that it may have been something from the beta? It may have even been the original waterway theme, but he may have thought it didn't fit the theme of the level, so he made/replaced it with living waterway, or it could have been in a different area entirely and scrapped. I'm not really sure, having never heard anything like it myself.

 

Weird... I haven't heard anything like Suiro before. It could be that it was some piece of music that conveniently just never got turned into an .org / .pmd format track.
Also I don't think it was actually intended for the waterway in CS, because in the beta CS Geothermal is used there, and Living Waterway is used in the entirely scrapped Frog Kingdom.