Go to the SCN mode, there you can click left or right on the wheel to see different specialty settings, such as fireworks, underwater, etc. One of your options is color accent. To pick which color to accent, click display. Then focus the little square in the middle of the screen on the color you want and click the left button. You can also change the tolerance by clicking up or down. Also try color swap, it's in SCN and is quite fun.