Change button color

Hi there,
I have a weird behavior when attempting to change button color.
I have a button created. Then I simply add a source image. Then I want to change its color. For two of my sprites, this simple action does not change image color. For others - it works.
Here are two sprites, which when used as source image does not allow to change button color:




and the next one is one, where the color can be changed:



I would really appreciate your help guys, thanks!

 

The color (tint) is multiplied by each pixel of the image. So black multiplied by any color would be black e.g. a black pixel from the source image multiplied by red (0,0,0)*(1,0,0)=(0,0,0) - black

Where as white pixel from the source image multiplied by red (1,1,1)*(1,0,0) = (1,0,0) - red

Hope this helps

 

Thanks, man, it makes things completely clear!