Products with different prices for options

Hi,
I have hikashop business most recent update.

I am trying to figure out how to give an option for different colored wheels with each color having its own price change.

Wheel Color:
Black (Default no added cost)
Silver $20
Copper $20
Rusted $25

Thank,
Charles

The problem I am having with setting as characteristic and then doing variants is that if I already have a variant section it does not allow me to create a separate variant drop down section without puting an input for the first variant section. So wan the variant for wheel color to be completely non dependent of the variant rails.

For example of my needs:

Variant Rails
Default 1/4 x 78
Rail 1/4" x 96 - $20
Rail 1/4 x 54 - $19
Rail 1/4 x72 - $20

Variant Wheel Color
Default Black
Rust - +20
Red - +20
Silver- +20

Not:
Variant Rails
Default 1/4 x 78
Rail 1/4" x 96 - $20
Rail 1/4 x 54 - $19
Rail 1/4 x72 - $20
Default Black
Rust - +20
Red - +20
Silver- +20