bumble beemer

A few months back I discovered that the air con was not very cold. I noticed fluid leaking from the general area of the bottom of air con radiator and air con pipe as pictured. I tightened the nut holding the pipe , I also fitted a new rubber gasket for that nut and then had it regassed professionally. I took this picture this morning which clearly shows ( yellow/green colour fluid) the leak is still present. Anyone else had this problem? Should I now replace the pipe ? or the air con radiator?