Sass - Assign variable with another variable

Question

I have this variable:

$color_pr1: #d6ad3f;

Now, I\'m using Gumby and it uses it\'s own settings sheet where the following is set:

Answer 1

From the docs: http://sass-lang.com/docs/yardoc/file.SASS_REFERENCE.html#variable_defaults_

You can assign to variables if they aren’t already assigned by adding the !default flag to the end of the value. This means that if the variable has already been assigned to, it won’t be re-assigned, but if it doesn’t have a value yet, it will be given one.

For example:

$content: "First content";
$content: "Second content?" !default;
$new_content: "First time reference" !default;

#main {
  content: $content;
  new-content: $new_content;
}

is compiled to:

#main {
  content: "First content";
  new-content: "First time reference"; }

Variables with null values are treated as unassigned by !default:

$content: null;
$content: "Non-null content" !default;

#main {
  content: $content;
}

is compiled to:

#main {
  content: "Non-null content"; }

Answer 2

Use css calc() function:

$header-font-color: calc(#{$color_pr1});