Try More Contrast instead of similarity.
Making your calls to action be a bit more prominent and distinguishable in relation to the elements surrounding them, will make your UI stronger. You can easily increase the contrast of your primary calls to action in a number of ways. Using tone, you can make certain elements appear darker vs. lighter. With depth, you can make an item appear closer while the rest of the content looks like it's further (talking drop shadows and gradients here). Finally, you can also pick complementary colors from the color wheel (ex: yellow and violet) to raise contrast even further. Taken together, a higher contrast between your call to action and the rest of the page should be considered.