How to use Flood Fill Tool?

[GuessANoob]

Hello -

 

Am new to Designer after using Photoshop for many years, and simply trying to fill in a solid color on a layer.  I tried the Help files, which explain what a flood fill is, but not how to use it.  I did locate it in the Pixel Persona.  Tried clicking on my layer, no luck.  Tried clicking in a mask, no luck.  Tried opacity setting slider changes, no luck.  Tried googling, but only find flood fill for other programs or else explanations on what a flood fill is.  

 

Any help appreciated, realize it must be a noobie deal and obvious once you know the paradigm.  

Thanks

[R C-R]

The Flood Fill (paint bucket) tool is in the Pixel Persona because it works on pixel layers, those labeled as "(Pixel)" in the layers panel. It will not work on vector shapes, or on "(Image)" layers unless you rasterize them first. It will work on Mask layers to apply transparency proportional to the lightness of the fill color.