I'd suggest running Ashnod's Altar, Ancient Den, and Master's Call, as that helps solve your mana issue, and opens the deck up to certain sideboard options, like Tempered Steel. I'd also consider Signal Pest.

You could also stand to add some card draw. Skullclamp might do the trick.

Thank you, those are great suggestions. I dislike splashing white just for those cards, but I agree draw is needed, and Ashnod's altar is good for mana. Also, if I have out Myr Matrix, I can sac all my creatures and maintain some of my creatures and mana.

I'd drop Myr Matrix entirely. Its ability is too costly. If you must have the indestructible, consider Eldrazi Monument.

Chromatic Sphere can provide simultaneous color fixing and card draw, and and only costs 1. I'd definitely be adding those alongside Ancient Den to make it less painful to splash white.