I never said you did. Something shouldn't be different just to be different, something should be done the way where it works the best. You said "at least it's different" implying that it would be better to be different, but it might not be as apparent on screen as the blue. Blue would probably work better in 3-D, and will look more pronounced in the dark. Imagine Electro shooting blue lightning down a dark street, then imagine a yellow Electro shooting yellow down a dark street. Picture that with each respective color reflected on the surrounding surfaces. Blue "pops" more. The yellow could appear dull and faded, while the blue they're using looks vibrant, dark shades, lighter shades mixed together.