You might want to read up on the preset manager in Photoshop.
And how to replace presets instead of appending them.
Oh I get it now, I have to click "replace brushes" instead of "load brushes". I never really noticed that option before. This makes things easier.
if I set a brush in preset manager with 'keep color' option... is there a way to bypass this (when choosing said brush) with a key command so I can use current fg/bg color?
Brushes don't have a keep color command, but tool presets do.
No, when you select the tool, all the settings associated with the tool are loaded. If you want another color, you'd have to select it afterward.
But you could select the tool, and create a new tool preset that doesn't include the color.