When you have the clip in the Timeline or Storyboard go ahead and left click on it. Go down in the pop up list menu, and select Video Effects. This will bring up the two column video effects menu, where all the available video effects are on the left-hand side and all the video effects that are on the selected clip are in the right hand column.
Go down, and find “Hue, Cycles Entire Color Spectrum" from the left-hand column, which is toward the middle right under Grayscale. Go ahead, and select “Hue, Cycles Entire Color Spectrum". Hit the Add button in between the two available columns. This will bring “Hue, Cycles Entire Color Spectrum" over to the right hand column and onto the video clip.
Now just hit the OK button, and it will be attached to the clip. If you want to remove “Hue, Cycles Entire Color Spectrum", then just right click the clip again, and open the Video Effects menu. Select “Hue, Cycles Entire Color Spectrum" from the right-hand column, and then hit the Remove in the middle to bring it back to the video effects left-hand column and off of your clip.