Reconstruct contourf image from triangle strips

Using the method described in

http://undocumentedmatlab.com/blog/hidden-hg2-plot-functionality

we can easily access to triangle strips at each contour level.

The contourf plot is very similar to patches (not equivalent), so I'm looking for a way to suppress some patches, for example, the patch with the concour line less than 10 points; moreover, give specific color to each contour level. I'm wondering how I can use the extracted triangle strip data for my purposes?