Easyblog 5: can't change the search area text color

HI
Whatever template I choose for EasyBlog 5.0.30 I can't modify the text color of the search area (for example).

In firebug even if I change the color in the div#fd.eb .eb-navbar-search .form-control, the color remains unchanged !

div#fd.eb .eb-navbar-search .form-control {
background: none;
color: #757575;
border: 0 !important;
height: 40px;
border-radius: 0;
box-shadow: none;
margin: 0;
}

Hence I can't override it. What is the right wqy to modify such properties please ?

thanks

cyril