Try using an SVG (vector file) instead of an image, there’s a plugin to allow SVG uploading in WP:
https://wordpress.org/plugins/svg-support/
GP doesn’t seem to allow setting the main logo in the SVG format but it works for nav and sticky logos.
Important: Make sure to only allow Administrators to upload SVG files because they CAN be used for XSS attacks, since SVG is not an image but a document file type that allows embedding scripts. However, the plugin takes this into consideration and hence allows for the role restrictions.