Color selector problem picking up color

[Giulio5E36]

Usually when I select a color from the palettes I made the color selector changed for the foreground color, but now, I don't now why, when I do the same thing the color selector use the background color and so I have to reverse the color selector every time I change color

[Michael Bullo]

Could you please explain exactly what you mean when you say "palettes". A screen shot could be very helpful.

Are you by any chance holding down the Alt/Option key while using the Eyedropper Tool? This key is what allows you to sample a new background colour as opposed to sampling a new foreground colour (default).

[Semaphoric]

Look at the Color panel. If you clickon either of the swatches in the upper left corner, it will make that the "active" color. They are highlighted, but is rather subtle.

Foreground Color:

Background Color: