Hi Carlos,
As the normal view of this interface has medium grey bars for the header and footer, this is clearly something caused by some custom (s)css in your theme. The secondary color (used for links) is the same green as the color defined for the header and footer of this interface.
If you disable the custom (s)css or switch to Boost / Classic theme using ?theme=boost or &theme=boost, you'll see where the differences come from.
As the normal view of this interface has medium grey bars for the header and footer, this is clearly something caused by some custom (s)css in your theme. The secondary color (used for links) is the same green as the color defined for the header and footer of this interface.
If you disable the custom (s)css or switch to Boost / Classic theme using ?theme=boost or &theme=boost, you'll see where the differences come from.