hi there,
I have already changed the color of the link in the customizer, however the color is still the same.
ifebug still shows:
a, .uk-link {
color: #de6e02;
cursor: pointer;
text-decoration: none;
}
and
a {
color: #5290d9;
text-decoration: none;
however this part is (new color) strikethrough
what do i make wrong?

A strikethrough is an indiz for an override:
You can add the color manually into your file: css/custom.css

a {color: #5290d9 !important}

Some things are better and faster to change via CSS then customizer.

thanks; I have already added this line to the customer.css ... still the original color.

Hallo, sie haben einen Syntax Fehler in ihrer custom.css

Falsch

h1, h2, h3, h4, h5, h6 {color: #5290d9};
a {color: #5290d9};

Richtig

h1, h2, h3, h4, h5, h6 {color: #5290d9}
a {color: #5290d9 !important}

Problem solved.