Build a 4x6x3 matrix in matlab, where each column of the image is a single color, in rainbow order. Experiment with different combinations of R, G and B to get the image colors right. (Hint: all the values in this image are either 0 or 1, except in the orange row where one of the three color components is set to 0.5). Very important: You must use for loops to assign values to the R, G and B layers of your matrix. When you are finished, you should save the image as a .png file using the imwrite command.