documentclass[11pt,a4paper]{article}
usepackage[T1]{fontenc}
usepackage[utf8]{inputenc}
usepackage[dvipsnames,table]{xcolor}   % »table« optons loads »colortbl« package

begin{document}
begin{tabular}{|ccc|ccc|}hline
  & Monday &  &  & Thuesday & \
  hlinehline
  1&2&3&4&5&6 \
  cline{2-5}arrayrulecolor{green} cline{2-3}arrayrulecolor{black}
  &&&&&&
  hline
end{tabular}
end{document}