how to colorize dynamically dynamics crm 2015 cases grid

Hi

I migrated from crm 4.0 to crm 2015(7.0.2.53) onpremise. I had colors in crm 4.0 by modifying grid.htc file (in _static/_grid directories)

Now i want to make the same thing in crm 2015.

I read about a tool in codeplex and i read also about subgrid. But i can't for the cases grid. this solution not good for my need.

The color must change when i change the case severity

here is the result i would reach

thanks

regards