Transparency for header

Hello.
I’m using HOTEL MASTER theme.
I need to apply some transparency to the top bar and the header, to look lie this:
https://www.losportaleshoteles.com.pe/hotel/chiclayo/

Besides, i need to add the translator button.

The theme options allow me to apply TOTAL transparency, but i need ONLY SOME transparency (50% aprox.).

Thanks in advance.