Bike color

In game I drive on Trek Emonda, but its impossible to change this bike color. On other bikes its possible to change color, but Trek Emonda bike color change is impossible, why? How to change that bike color???

It is very subtle, but there are some decals on the top tube which do change color with adjustments of the color slider.  At least, that’s what happens during customization on the iPad.

The Emonda is a climbing bike.  Extra paint makes it weigh more.

 

Additionally, sometimes bike manufacturers only want their bicycles to appear in Zwift with specific color-schemes.