Change To Colour Effect

I found an effect which would gradually allow me to change the colour of the video. This means a colour would morph from one colour to another, this can be seen in the picture below. I decided to change the yellow graffiti to red over a 3 second period. This is very effective and keeps the audience concentrated as it is not an everyday occurrence. I selected the colour dropper tool to select the original colour, and transformed it to a colour palette chosen red.