Default [Q] Pink Screen on the boot

Hi everyone, i flash purity rom and franco kernel on my Nexus 7 2012. 4.4.2 and then i reboot it. theres a Pink flashing on the screen after the the Logo of Google and before the Logo of Nexus on the Boot. why is that happening? is theres a problem on the rom or kernel? or etc.. before then i was on stock 4,4,2 there no pink screen issue i experienced.

Guys please let me know what the problem is. help me please. (Semi Newbie Here)
Thanks in Advance!