Yep, needs to be the same color. Lots of the MB parts are the same except the color...transmission modulators, check valves, temp sensors, the themo vac switch, wiring and vac lines, etc The only diff on lots of these is the color of the top plastic indication at what value it activates.
Yours needs to be red.

__________________
Christopher Henkel
1990 190E 2.6 - Arctic white SOLD
1986 190E-16v - Blauswartze
1993 300CE - SOLD
2003 W208 CLK 320 Cabriolet - Magma Red