Per face vertex coloring In blender you can color the vertexes. But is there a way to color the faces so the faces have only one color instead of the colors being interpolated based on the colors of the surronding verticies. This is avalible in maya ( https://youtu.be/TxlASKUMgfo?t=1m10s ).
Adjacent faces can have different plain colors, and a vertex can have a different color for each face it participates to.

In 2.79, it's possible to select the faces in Vertex Paint mode, and use 'Set Vertex Colors' (Header > Paint menu or Shift-K).

  

Likely the integration in Blender of a separate script that was used before.

Edit:


To view colors in the 3D editor when 'Material' display mode is selected, the option 'Vertex Color Paint' must be enabled for the material used (Properties editor > Material tab > Options panel).
The 'Face Selection Masking for Painting' button must be down in the 3D Editor header (Vertex Paint mode).