You could interpret it this way. That's obviously what the filmmakers seemed to intend with the effect. I'm not sure it would change with other emotions, though.
One detail that I always found interesting was that, when Roodaka's eyes change from anger, they turn from blue to the normal red-yellow of the other characters:
Whereas, when she's charged with Makuta's power, her eyes are bright red with white, like the evil characters:
I always thought that the BIONICLE films were interesting in their use of eye color for good and evil. Normally we would associate a color like green with health and goodness and red with evil, but BIONICLE flipped that around in some cases, with green representing corruption, as with Tahu and Vakama.