How to add custom colors for badges of sphinx-design?

[hwhsu1231]

Based on Badges, Buttons & Icons of sphinx-design docs, we can use the following colors for badges:

:bdg-primary:`primary`, :bdg-primary-line:`primary-line`
:bdg-secondary:`secondary`, :bdg-secondary-line:`secondary-line`
:bdg-success:`success`, :bdg-success-line:`success-line`
:bdg-info:`info`, :bdg-info-line:`info-line`
:bdg-warning:`warning`, :bdg-warning-line:`warning-line`
:bdg-danger:`danger`, :bdg-danger-line:`danger-line`
:bdg-light:`light`, :bdg-light-line:`light-line`
:bdg-muted:`muted`, :bdg-muted-line:`muted-line`
:bdg-dark:`dark`, :bdg-dark-line:`dark-line`
:bdg-white:`white`, :bdg-white-line:`white-line`
:bdg-black:`black`, :bdg-black-line:`black-line`

I wonder whether it is possible to add custom colors for badges. For example:

:bdg-custom1:`custom1`
:bdg-custom2:`custom2`
:bdg-custom3:`custom3`
:bdg-custom4:`custom4`

If so, how to configure?