Roof tiles random colors is the most recent collection of high quality model tiles that you can use in 3D modeling. They perfectly match any architecture, even if it's quite complex and unusual. So, the best way to find the right roof tiles texture for your design is not looking for some mixture of colors, but randomly picking a few of them from a huge range.
With the road issue, always download assets directly from Sketchfab site if you want to edit them more. There is an option within Twinmotion to click on the asset and go to sketchfab site to download it. Then import it from where you saved it into your scene.