Another option for adding blur is to use “Pixel Motion Blur” (built-in) or Reel Smart Motion Blur (Re:Vision FX plug-in) in After Effects. If you crank the samples up, you can usually avoid nasty artifacting, depending on how complex the scene is.
If you are running a compatible graphics card, install the latest CUDA drivers and then in your project click file>project settings>general>renderer>select the Cuda option.
I first noticed this issue with 2013 CC. The issue still seems to happen in 2014. Trying to add three-way as a master clip effect and getting the green shift. Anyone else seeing this?