I would actually play devil's advocate to everyone else on this forum, and say YES, I WOULD recommend enhancers for a better color change for your particular eyes.
I say that, because enhancers are meant for people with light colored eyes such as yours. They are tints over the entire contact, so your own natural pattern still shows through, while the color itself is changed to whatever the tint is. Acuvue only has green and blue enhancers, however, other brands even have BROWN enhancers for light-colored eyes that would make your eyes brown, while others have violet, yellow...etc. Because you have a pretty much white palette, any color would be very noticeable on your eyes, and you can change your eyes to any color of the rainbow while still maintaining your own natural eye pattern and depth.
Opaques are just said to be more noticeable b/c they are painted-on colors instead of just tints, so yes, they would cover up dark colors well and really change eye colors for dark-eyed people. However, b/c it is a flat color, they can easily be spotted, can have a fake-looking pattern to them, and they all have a blunt pupil hole that totally gives them away if you have light colored eyes underneath.
(exhibit A, my Sapphire Acuvue 2's
Basically, Opaques are used usually on darker eyes to change them dramatically; usually to make them lighter. Enhancers change tints on light-colored eyes like yours, and can be just as dramatic on light-colored eyes as opaques on dark-colored eyes. So, unless you want to make your eyes even lighter (White or gray), I recommend enhancers. Or, pick opaque lenses that blend into a blue/gray near the pupil hole, to match your eye color. =)