Here's what i did:
1) Take out the gauge from the car, make sure your fill up that fuel tank to full beforehand.
2) Pull the rpm and speedo needles upward a little and let it rotate to its natural position instead of being stopped by the stopper on the gauge.
3) Rotate the needle to COUNTERWISE by 180 degrees, let it rotate back ito its natural position, use 3m clear tape to mark its position (also use 3m tape to mark the the full fuel position). Do this a few times to assure an accurate marking spot. This step is only for the rpm needle and speedo needle
4) pull out all 4 needles, sand down the red color using sand paper.
5) paint the back of the needle with 1:18 model paint
6) put everything back together other than the fuel and temp needles, make sure the rpm and speedo needle rotate back to the same marking spot after you rotate them 180 degrees COUNTERCLOCKWISE. The natural position for the needles rotating clockwise and counterclockwise are DIFFERENT.
7) connect the gauge to the car and don't put on the transparent cover, drive the car around for 10 mins or so, put the temp needle back pointing little bit downward from center.

enjoy your new needles