%! TEX program = lualatex
documentclass[]{article}
usepackage{luatex85}
usepackage[xcolor]{changebar}
usepackage{lipsum}
cbcolor{blue}

begin{document}
lipsum[2]
cbstart
{color{blue} % I want to remove this here and add a configuration to the preamble.
  lipsum[2]
}
cbend
lipsum[2]
end{document}