I use an White Logo in the Header and the logo is not shown on mobile view, because the header background color is white.

How can I use a transparency header on mobile or another color for the mobile view?

Thank you
hnsm.

In that case you may set your mobile header background color explicitly in Theme Options -> Custom CSS or in your Child theme CSS file like so:

@media only screen and (max-width: 768px){
  #header {
    background: #666;
  }
  .m_nav_ham {
    background: #fff;
  }
}

Notice I also set the MENU NAVIGATOR to white color in there.

#header {
    background: #1A1A1A;
}

@media only screen and (max-width: 768px) {
  #header {
    background: #1A1A1A;
  }
  .m_nav_ham {
    background: #fff;
  }
}

Simply add the !important clause to your CSS:

@media only screen and (max-width: 768px){
#header {
    background: #1A1A1A!important;
}
}

@media only screen and (max-width: 1017px){
#header {
    background: #1A1A1A!important;
}
}

You may want to force the mobile menu to be white as well:

@media only screen and (max-width: 1017px){
.m_nav_ham {
    background: #fff;
}
}