how do I save my colors on blender to convert them over when uploading on sketchfab?

Hey Terence, if you export as an OBJ (with the automatically included MTL), the basic colors should transfer over to Sketchfab. If not, you may have to adjust them in Sketchfab's material settings: https://help.sketchfab.com/hc/en-us/articles/202600873-Materials-and-Textures