Quoted from luvthatapex2:

The way it always works for me updating the display:
1) download the rom (chroma.rom in your case since you are using a new display board) and copy it to the usb stick. This should be the only file on the usb stick.
2) turn off the game. insert the USB stick. turn on the game.
3) once booted, hold the first button on the left down down and watch the display board blink 5 times. This is the button closest to the ribbon cable. It should start downloading the rom and you can leave go of the button. The display will now be BLACK as its getting updated, then around 45 seconds later, the display will turn on with the color rom loaded.
This video from color dmd shows the process. start at 1:17 to update the display. again disregard the filename in the video, you need the new chroma.com, but the rest should be correct.
» YouTube video

Quoted from luvthatapex2:

There can be other files on the stick, I was just simplifying the procedure to guarantee results. The loader is going to look for the file in the root directory of the stick, it won't look anywhere else.

Quoted from Dmod:

Other files can be on the USB drive.
Take it step by step and watch the PROG LED.
(1). Power the board on without the USB drive. THe PROG LED will blink briefly at power up and the board should boot to DONE. DONE indicates that the boot process is completed.
(2) insert the USB drive. PROG should blink once on mounting the drive and go out. If PROG keeps blinking at this stage there is a problem with the USB drive. You'll need to reformat the drive with MS-FAT32 or purchase a new drive. MS-FAT32 is the formatting used for new drives.
(3) Press and hold the left button. PROG will blink slowly 5x and then go solid for the installation. When installation is complete the PROG LED will turn off. IF PROG starts repeatedly blinking here there is a problem with the filename.
If the filename looks correct and doesn't contain any additional characters you may have a hidden double extension (chroma.rom.rom). You can try deleting the visible extension. Turn the power off and on again and repeat the process.

Quoted from Dmod:

The STATUS LED doesn't really do anything except light when you're pressing buttons. It's controlled by an embedded processor so it provides evidence that the chip has booted and is working properly.

Quoted from Dmod:

Great! Glad you got it working.
DOTS is the style closest to the original DMD but must people prefer DOTXL over DOTS which makes the display brighter and improves the contrast.