If you want to change color of products slider arrows you need use some image editor because they are loaded from the directory wp-content/themes/blanco/images/slide_next.png and wp-content/themes/blanco/images/slide_prev.png.
Your site is displayed well on mobile devices. Please clarify what is wrong with responsiveness.
Also the currency is set to $. Could you please clarify with more details?
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.