Excel coloring forecast area

Dear forum members,

for the last couple of hours I have been trying to color the upper and lower area of a forecast. I have been able to color the upper part but struggling to color the lower part as well, see attached screen shot.

Do you have an idea / solution how to color the lower part as well?

Thanks a lot for your help and sorry for my bad English, its not my mother tongue.

W0rldTrav3l3r