Relight tool icon:
https://www.svgrepo.com/download/10248/camera-flash.svg
Released under CC-BY-4.0 (https://creativecommons.org/licenses/by/4.0/)
Modified to fit the overal color schemeof the application

Alternative versions:
https://www.svgrepo.com/download/30725/flash.svg - Released under CC-BY-4.0 (https://creativecommons.org/licenses/by/4.0/)
https://www.svgrepo.com/download/158544/camera-flash.svg - Released under CC-BY-4.0 (https://creativecommons.org/licenses/by/4.0/)
