can I change the Scan Barcode button to another words? and how I can change the button color also?

can I change the Scan Barcode button to another words?

and how I can change the button color also?

This is possible, but only by injecting custom CSS code into the widget. 

Here is a guide: How-to-Inject-CSS-Codes-to-Widgets

I can suggest the following code: 

#scan {color: transparent;background: green;}

#scan:after {

content: 'Test';

position: relative;

top: 0;

left: -30%;

color: white;

}

You can replace 'green' with any color you need and 'Test' with a text for a button.

We will be glad to assist if you need more help, just let us know. 

may I ask how you know that button's variable name called scan?

You can locate that in browser dev tools. If using Chrome, just press F12 and press and hold CTRL + SHIFT + C and hover your mouse over the button.

Ex.

Let us know if you have any questions or if you need further assistance.