Inserting multiple columns into an existing matrix in equal distance

I would like to break down the red matrix (see below) into 3 columns and insert each column in equal distance into the yellow one.

Answer 1

[James Tursa]

E.g.,

yellowx = reshape(yellow,[],size(red,2));
result = reshape([red;yellowx],size(red,1),[]);

[Saeid]

Thanks, james!