Kids Book about an Evolving "Smush" of Paint

[Scribh]

This recently popped into my head out of nowhere - I'm fairly sure I read this children's book either in Canada or the United States between 1992 and 1999 and it was intended for ages 5-7. In the story, there is a colorful watercolor blob, or smush of paint that eventually gets legs and develops into something more substantial as the pages turn. I remember the line 'but it was only a little smush.' Google Books and Amazon haven't turned up anything relevant so far.

[Rainbowheart]

Smudge?