Add background default

[danielclickh]

References: Multi-accordion example | Storybook component

To make sure we have enough contrast on dark mode when used on flyouts, let's add click/global/color/background/default. On lightmode the background will be the same, but the stroke has a better contrast than when in dark mode.

Example:

[danielclickh]

@natalyjazzviolin do you mind taking care of this one? That will help with the dashboards flyout.