Rain rig is black when I try to link it to a new scene

[Nuke_Crayon]

How can I show the color in the solid view mode?

[ShankarJ]

Color means? are you asking about the texture of an object?
Select object > Apply a texture > Go to Display in solid mode panel in viewport top > Choose texture

If you want solid color then
Select object > Object properties > Viewport display > Change color > Go to Display in solid mode panel in viewport top > Choose object

If you choose random, Random color will be shown for all objects in the view port

[Nuke_Crayon]

thank you very much!

[ShankarJ]

Welcome!