Grid Locked Columns - change background colour

[Trevor]

When I add 'locked: true' to a column, the column automatically gets a white background rather than a transparent one.  This means that when I hover over a row, the locked columns don't highlight.  How do I change this?

[Plamen]

Would you please specify how to achieve the desired behavior or which theme should I use because I could not observe it in a quick test at my side - https://stackblitz.com/edit/k3tndv?file=src%2Fmain.vue ?

I will be looking forward to your reply.