I started creating this by hand when I taught first grade. Now that I'm a little more computer savvy, I have created several. The idea is a shape traced onto graph paper. Students color following a pattern inside the shape and a different pattern on the outside.
I have this heart printed on three sizes of graph paper in this free Google Doc.
If you are planning ahead for next month already, visit this post where I linked the Shamrock version of the same activity.