Well I haven`t actually done it myself but I would assume that you have to combine the colour of the texture in that area with the alpha to change the tinting effect.
If the texture shows green there andthe alpha 50% then you should get green tinted semi-transparency for example

To get no tinting I expect the texture would need to be white where the window is but if that doesn`t work try black.

It may of course be one of these things that can`t be done using just the texture. The other examples you have seen may have had the transparency applied in the model itself