Loosing part color in assembly when using save as

Hello together,

since we change from Wildfire 4 to Creo 4 i have a problem with color in assemblys when i using "save as" to create a new assembly.
The assemblys are generic and family based. A lot of the integrated parts are also generic and family based.

Example:
asm_genreric (with instances e.g. "asm_1" and "asm_2")
--part_red (generic with instances "part_red_1" and "part_red_2")
--part_blue (non generic)

All parts are colored (red / blue) before they are inserted in the assembly. The color should be always the same.
No color assignment is made in the assembly!

When I open a instance assembly e.g. "asm_1" with the part instance "part_red_1" and using "save as" and open
the new created assembly the "part_red_1" is no longer red and have the standard Creo color.
The non-generic part "part_blue" is blue.

I try this with Creo 4 and Creo 6 (new standard installation) and the system colors. With standard material assignment and without.

In both cases I have the problem, that the instance parts loosing their color.

Have anyone the same problem or maby a solution? Thanks.