rainbow

I have a rainbow in the pictures. How can I make his colours more strong and more visible? Thank you very much.

it would help to see the pic in order to provide a meaningful answer. There are a number of things you could do - make a mask and use Color Balance to add a little life to the colors... you could use Color Range to select the rainbow and then enhance the colors with a little hue&saturation you could also manually paint over with the Sponge tool set to saturate... you could add an adjustment layer to it and bring out the contrast in the rainbow....any of those would do the trick.