I have the backlight hooked up to 5V and I use a resistor only if I want to decrease the brightness, and no resistor has been working fine. Then I have the one that lights up the pixels hooked to 5V with no resistor, and it worked fine for a while but now if I have it active for more than a few minutes the pixels start to fade, like an overdriven LED, and they go back to full brightness after the Arduino is turned off for a while.
Do I need a resistor connected to it? If so, how small can I get and still make it have an effect? Because a 330 ohm is drastically decreasing the brightness of the pixels and I'd rather not do that.