Changing colors of COLLADA files (textures in .dae files)

please accept my apologies if my question sounds very primitive.
i am having the following problem.
has anyone had any experience on changing colors of textures in the
COLLADA files? according to my experience, the colors donot change
much maybe because of the fact that my original texture has gray
background color (jpeg image). which parameter should i change/play with most? i tried <ambient>, <emission>, <phong> etc.
best regards,

It depends on what the viewer you are using is doing with that information.
It may simply use the texture as a replacement for any other color information.

Hi Remi,-
Thanks for your reply.
i am using Google Earth (GE) to visualize collada geometries with textures.
By the way, Google Earth is not able to visualize collada polygons.
do you have any collaboration with GE on this issue?
i believe that i should be able to change color of textures and i can for big colir changes like pure green, red or yellow. however, the colors in between donot have much effect.