White theme nextcloud

Hi all!
Recently I decided to change the look of my Nextcloud server (NC15) but i realized that when I choose the white color in the theming option, the status bar when uploading files and the capacity percentage bar, in the bottom left of the screen does not show correctly, because of the color chosen.
I mean, when you choose the blue color, the bars show a blue part that shows the amount of storage you have used or the progress in an upload, buuut when I choose white color, the backgroud is white too, so i cant see the “progress” of an upload or the capacacity % of usage. Do you know if it is possible to change the color of the progress bars, so I can have the white bar over a grey or black background, like the icons in the upper bar of nextcloud (notifications, search, gallery and so on)
Thank you so much for your help!!