Sanco Industries Mulchworx Mulch Color Concentrate - 2,800 Sq. Ft. - Pure Midnight Black Mulch Dye Spray Black

Once you open and use it do you need to use it all at once, or can you store the rest for next season?

How long does it last on the mulch? Days, weeks or months?

Will it stain after drying? Will I be able to walk on the mulch after watering the plants or rain without turning my shoes black ?

What about flowers? How do I void not to get on them ? And also is it bad for the flowers will ?