You'll need some training to go with the dyes from Chemspec. Dyeing/colour repairs are amazingly involved and complex. Not for the feint hearted. Don't use bleach on wool, you'll dissolve it

I feel it would be wiser and more cost effective to buy a new carpet. You can only dye a carpet darker, not lighter. If you have a carpet with, say, a yellow stain, dye it blue and you'll end up with a green stain

So bear in mind if there's a faded traffic lane, dye the carpet and it will still probably be a faded traffic lane but in a different colour.
Safe and happy colour repair

Ken