[Inkscape-user] Perspective to multi colored composed objects

In the attached SVG/screenshot you'll find three objects. The first is composed by multiple objects of the same color, combinated into a single one in order to apply perspective - which was succesful as seen below it. Now, the other two are composed by different colored objects and I want to apply perspective just as they are. However, that can't be done on multiple objects, and when combinating or blending all composing parts merge and turn the same color. Any solution? Please help. God bless you.