When exporting a .obj or .fbx how do you keep the color/texture? I've been looking up tutorials and sites for days now to help me figure this question out, but nothing has been working for me. I am fairly new to Blender, so this is a new experience for me! I know that UV Mapping may have something to do with it, not quite sure. 

Here is a simple tree I made on the right. I followed this tutorial: https://www.youtube.com/watch?v=kqjOiBvrVtg



However, every time I try to export it and import it into ROBLOX Studio, I get the picture on the left:

What would the best solution be? I also would like to know how to do it if I did add textures and not just plain colors (unless they follow the same procedure). 

Sorry for the nooby question, thanks again:)
Unwrap your model, create new material and assign a jpg texture to it (or create new in in Blender's UV/Image editor and paint it in Texture Paint mode).

Export the model to FBX.
Open Roblox Studio, create MeshPart object and import the FBX using the Open Mesh File button


Texture should be assigned automatically



If you want to use simple colors instead of textures, you can use Vertex Paint mode and color your model using this method. Roblox can import vertex colors contained in your model (if not, make sure you have ticked export vertex colors in the FBX/OBJ exporter dialog in Blender).