Radio Shack carries standard sized LEDs. These may or may not be the same physical size as the ones on your front panel. Generally, these run off the 5V side and they do come in colors. The HD indicator LED is wired to the MB as is the power LED and sometimes others. LEDs are polar devices. They can only work when properly biased. In some cases, a current limiting resistor is needed. You will need to find the front panel connection pins on your MB and find some way to determine which goes to where. A DVM would be extremely handy as is a good low wattage soldering iron, some heat shrink tubing and decent skills at using these.
I haven't come accross it yet, but I was wondering... Most computer cases have 2 LED lights on the front, one for power, one for the HDD. Is it remotely possible to change those easily? I dont particularly like the ones I got with my case, and went to some electronic stores to see if they're replacable and couldn't find anything in the moding section. I want to have a blue and red or orange or something... All I've found so far are those LED lights that you plug into the powersupply to light up the inside of your case. What I am specifically looking for are LED lights that you can plug into your motherboard to indicate power on, HDD reads form the motherboard POWER and HDD leads.
Ideas? Help? Or is the thing I'm searching for impossible?