If you pick Viktor
and manage to gain 2000 gold and back buying his second staff 
straight up it will only give you one spell upgrade instead of two, then when you pick up the finial one
it'll give you another but you will miss out on chaos storm's upgrade and one of the other ones you didn't pick. So till they fix it I would recommend just buying them one at a time
it doesnt happens to me, but im from EUW, so thats probably a bug of NA server
I had time to reproduce it twice, will try again after work tonight.
It is because the game is programmed that yellow is an upgrade, blue is an upgrade, and red is an upgrade - there is not actually a bug here, the augment is working as it is intended to work as - just an over sight because in a real game you will be buying only one augment at a time like how the game was programmed for it to work- in order for the augments to do multiple upgrades at a skipped purchase that actually needs to be programmed into the game so this may not happen until a couple of patches in the future- but Riot most likely has seen this feedback multiple times and will have a fix a.s.a.p.
