This is the Cyan & Magenta Portals Vines with a customised mask.
Blue & Pink Vines Portals are the 2006 Beta version of the Portals made by valve. I have modified the normally orange Vines portal to be pink (Magenta) like the Portals seen earlier in development. The mask has also been painfully upscaled, and cleaned up frame by frame to be cleaner. In this mk2 version, the mask has been modified so the outer edges of the vines do not cut into the walks to be visible through the paired portal. This is on my personal interpretation that the outer edges of the vines would be too weak to sustain and create a stable portal, so the outer edge vines fade away without creating a portal to the other portal.
To install you must first decompress the the portal_custom_vines_mk2.rar file. Then if you haven't already, go to C:\Program Files (x86)\Steam\steamapps\common\Portal\portal (or where ever your portal is installed) and create a folder called "custom" without the speech marks. Like so: C:\Program Files (x86)\Steam\steamapps\common\Portal\portal\custom You then drag the decompressed portal_custom_vines_mk2 folder in there and everything should work fine.