Common issue being reported:
I can't see the color trails/there are no color trails
The color trails are a separate "rule" from the two "lose if you step on (opponent/your) color" rule. Because of this, it is very possible, and it fact the more likely outcome, that one of these lose rules will be drawn before color trails are left.
My opponent isn't following the rules
I believe this is due to my quickly and terribly implemented UI. The list on the left of the play field is simply letting you know what rules could be added next time a rule is added. They are not rules. Pressing E will give you the list of rules.
I believe this is what is happening as I have been unable to replicate the complaint of the opponent not following rules