In the episode where Trudy is sentenced to death by the guardian, Lex is witnessing her sentence and leaves the Mall. When he entered the Mall, his facial make-up consisted of three black waves on the right side of his face, as he leaves, his facial make-up is back on his left side, a thick red line and a thin red one.
When Sammy drinks too much and passes out, the make-up on his forehead is the green tic-tac-toe design. This is still visible when Gel leaves him to sleep it off. Later, when the others find him, his make-up consists of three multicolored stars.
In the first episode of the first series when Lex is speaking to Zoot and the Locos he's asked why he wants to be a Locust. When he struggles to answer the question he responds by reading graffiti on the wall which read "Locos are scandalous" and replies to Zoot "You're scandalous". However later in the series when Lex is trying to cook for Zandra; Lex reveals to KC that he can't read.
After learning from Pride that Amber could still be alive, Dal checks her grave to find it is empty. Lex refuses to let Bray disturb Zandra's grave because he put her body into himself and is certain is is there. This means that the Mallrats somehow managed to bury Amber without noticing that they didn't have a body to put into her grave. Being unable to find a body should have been a big clue that she may not have been killed in the same accident that killed Zandra.