Twisted Fate's E (mabye QOL not bug but pretty sure its a bug)

When you put a point into twisted fates e it doesn't change colors. When i play a champ i typically just put a point in every skill before i max out something. This is weird for tf because when u put a point in it it doesn't show that u really did by changing the icons color. This causes me to put unnecessary points in the ability early in the game. If this isn't a bug please fix it as it is extremely annoying and would help. (yes ik im a n00b for putting a point in everything without thinking, but it still shouldn't be like this in the game.) Thanks!