I believe thede door sill plates are electroluminessant. Switching to red or actually orange (closest you can get) is a little tricky but not impossible. An EL is a plastic laminated phosphor materal that glows when electric current is applied. Very few companys make these and the wholesale/retail market is small due to the fact that everyone is customized. I can try looking in a few lelectronics catalogs for you but i doubt ill find anything.
Next best thin is just place some red filters between the EL and the cutout and instead of blue/green youll get a little less bright red!
Good Luck!
Adam

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Current Stable:
01 ML55 AMG
92 500E (a few mods)
87 300E (lots of mods)
00 Chevy 3500HD Diesel Box Truck
68 18' Donzi Marine
06 GT i-Drive7 1.0 Mountain Bike (with GPS!)

PREVIOUSLY OWNED:83 300SD, 87 420SEL, 88 420SEL, 90 420SEL, 86 560SEL, 86 190E 2.3-16V AMG, 94 E320