[Affinity Publisher - Colour Replacement]

I'm currently struggling with the same thing-- is there not a plain ol' selection tool in Affinity?

I have downloaded a white IG logo.png for a CV. I just want to select the white logo (translucent background) and fill it with another color so that I can see it on a white background. I feel like I have done this a million times in Adobe, but feel super silly for not finding the right tools to click on here and the tutorials I find online refer to the selection tool that I am used to seeing and cannot find in my toolbar.

whut.