If you download icons individually you will be able to change the color of the PNG/SVG icon file types.
Once you select the file type you desire a colour menu will displayed and you will be able to choose between the offered colours or choose the colour you desire.
If you desire to change the color of the icons of your collection you can do this in two different ways.
You may change the color of all your collected icons by clicking on the palette and this will display a color menu for you to choose the one you desire.
If you desire to change the color of your collected icons individually you must click on the pencil and here the palette will appear where you will be able to choose the color of the individual icon.