the eis will still require correct programing using the mercedes factory tool even if you have the orange key. if this was done correctly all keys should work if they actually function correctly. or if you did program with factory tool, it is possible the inoperable keys inadvertantly had their key tracks disabled, but i think more likely incorrect version coding. as for the orange key, when we install EIS units for customers the orange (previously green) keys were given with a core deposit, which was always given with a refundable deposit, i personally like the chrome keys, they seem to be able to withstand dropping better, less plastic i guess.

__________________
1967 250 S
1967 280SE
1968 250S
1971 280 SE
1973 220
1974 280 S
1975 450 SEL
1976 220 D
1979 300SD
1983 300 SD
1985 230 TE euro
1986 280SL
1986 500 SEL euro
1986 190E 2.3
1990 300 SE
2003 C230 K
2004 C230 K
1987 560SEL
1987 300SDL now in canada
2005 C230
1998 C43 AMG Sold to DON
1993 190E 2.6
300TD Former daily driver Totaled
current:
R320 CDI
Ram 2500 Cummins