some helpful cvars:
// Amount of ping bars shown, the more ping bars, the more precise ping will be shown
seta cg_ScoresPing_MaxBars "10" (default value is 4)

// Ping interval
seta cg_ScoresPing_Interval "30" (default is 100)

where to search for vista: (file: config_mp.cfg)
C:\Program Files (x86)\Steam\steamapps\common\call of duty modern warfare 2\players

when all green bars are full, then your ping should be around 30. when you have 1 red bar then your ping is around 300

 If you have any questions hit me up and I will assist you its E Z :P

This is not illegal or considered hacking

Thankx AZTIG_Bang for the usefull tips