I add the fifth parameter, alpha, to let user choice of transparency level.
[14/06/2017]: the function should return the handle to give control for fill shape.
BINH PHAM (2020). ciplot(lower,upper,x,colour,alpha) (https://www.mathworks.com/matlabcentral/fileexchange/63314-ciplot-lower-upper-x-colour-alpha), MATLAB Central File Exchange. Retrieved .
With the handle to fill region, user can control for excluding legend as shown in the picture.
Inspired by: Plot confidence intervals