documentclass{article}
usepackage{xcolor}
usepackage{hyperref}

definecolor{mygreen}{RGB}{176,232,145}
definecolor{myblue}{RGB}{61,139,189}
definecolor{myorange}{RGB}{245,156,74}
definecolor{mypurple}{RGB}{230,111,148}

hypersetup{
  colorlinks=true,
  urlcolor=red
}

begin{document}

href{www.tex.stackexchnage.com}{TeX.sx}

hypersetup{
  colorlinks=true,
  urlcolor=cyan!50
}
href{www.tex.stackexchnage.com}{TeX.sx}

hypersetup{
  colorlinks=true,
  urlcolor=mygreen
}
href{www.tex.stackexchnage.com}{TeX.sx}

hypersetup{
  colorlinks=true,
  urlcolor=myorange
}
href{www.tex.stackexchnage.com}{TeX.sx}
end{document}