jerryronchie

Some tires have a heavy duty rating & are very stiff with deep tread. Deep tread causes the air to literally flow through & make the noise. I think this might be the reason behind the humming noise from your tire.

You won't get the perfect match but you can try over local auto part shops near by you. I have a 92 Lexus SC with stock rims and I found the duplicate colour resembling to Dupli Color Silver Charcoal from local store only.

As far as I know if the car doesn't come with HID you will find instructions in the manual and if it does come with HID then they don't telly you how to do it.