I am using MATLAB I would like to plot a colourful trajectory on top of a grayscale png image whilst retaining the colour information of the trajectory. For example with the data below, I would like to plot Data B over Image A. Without Data B turning gray and without making the colourbar represent the grayscaled image. Any help would be greatly appreciated!

%Image A
RGB = imread('peppers.png');
I = rgb2gray(RGB);
figure
imshow(I)

hold on