The texture is 4096x4096. Taken from MakeHuman Community asset repo and can be useful as a guide for marking seam and unwraping a humanoid 3d character.

FROM THE ASSET REPO:

This is a demonstration skin which marks locations of various body areas and seams. Connection points are labeled with letters and colors. Outside the skin texture as such, there are explanatory labels. The XCF file has the labels on separate layers.

AUTHOR:

This texture and it's source file were submitted by Joel Palmius on MakeHuman Community asset repositories under CC0 license. There are also .mhmat and .thumb files in the repo: http://www.makehumancommunity.org/skin/annotated_skin.html (does not support https)

The author is one of the developer of MPFB2, free and open source human generator for Blender. Author's github profile: https://github.com/joepal1976