I want to color only the selected texts but it will color the non selected areas for no reason...

Hi,

Whenever I want to only color in the selected texts, such as just painting in a white color,  Photoshop will also color in the nonselected area around the text which is really stupid. Please fix this ASAP!

I noticed when I color in the selected text with black it does change any color around the selected texts.. Something is definitely wrong here...