XF 1.5 How to change view and comment number colour?

Dear all.
Please Show me the code For auto change colour:
ex: When Topic View <500, View number colour is Black, When Topic view 500<=view<1000, view number is Green and Bold, When Topic view >=1000, view number is Red and Bold.
Comment the same:
1. Before:

2. After:

Tks for all!