SbColor(3) on Linux
The text 851b38d27a82, as Debian 8 (Jessie) shipped it.
The SbColor class contains the red, green and blue components which make up a color value. This class is used within other classes in Coin. It inherits the SbVec3f class, interpreting the 3 component vector as a vector in the RGB cube where the red, green and blue components corresponds to x, y and z respectively.