Nether Brick and Concrete (Purple concrete as example) Has a Graphical glitch that shows the border of every block. Giving off this weird Checker look to it. So far could only see the glitch on those two blocks. Every other block, At the time of posting this, looks normal.

Below is a picture and video of what i mean. They may or may not be easy to see

 
Edit: Tested with the original texture pack and the lines are gone. Currently was using SPhaxpurebd in which it must be a TP bug