Change background of screenshot corner according to light/dark mode

Can BTT use a white background for screenshots in the light mode? See screenshots below, a black background is used for both modes. The black background in light mode is visually distracting.

light

dark

By the way, the BTT screenshot is very convenient and I use it nearly everyday.

The dark corner is a result of the JPG format selected when configuring screenshot capture. If PNG is selected, the background is blank. Unlike the macOS system screenshot, BTT compresses the PNG, with a comparable size to JPG. The compression makes the PNG format viable in terms of file size.

Notes added: For "whole screen", the screenshot does not seem efficiently compressed as a PNG. I choose JPG for the full-screen capture because there is no rounded corners to worry about.