Azathoth: A not-especially-subtle visual clue that is still rather easily missed: Unit 00 is without her pylons. For the rest of the series, whenever the pylons come off, you're in for some serious shit. (These later instances suggest that the original purpose of the pylons may have been to prevent an Eva from manifesting AT-field wings, as seen in the OP).
jetatomic: This cut would be reused again in episode 14.
Fireball: Personally, I prefer the later used blue color scheme. Aside from the similar hair color, blue is the color of the element water, which Ayanami is heavily associated with (her name meaning "twill wave", fly me to the moon ending etc). blue stands for innocence, loyalty and often represents the human emotion of sadness. Quite the fitting color for our calm demeanor girl.
To add as well, in the series orange is associated with LCL and is the complementary color to blue. Yeah, the designer in me is speaking right now.