function image = color_fluor(start_dirname, experiment_path, display, save_flag)
    frame = 213;
    filenum = sprintf('%04d', frame);

    fret_dir = start_dirname;
    cy5_dir = start_dirname+1;
    cy3_dir = start_dirname+2;
    txred_dir = start_dirname+3;
    
    fret_name = sprintf('%03d', fret_dir);
    cy5_name = sprintf('%03d', cy5_dir);
    cy3_name = sprintf('%03d', cy3_dir);
    txred_name = sprintf('%03d', txred_dir);
    
    fret_filename = [experiment_path '/IMAGES/RAW/' fret_name '/SC_' filenum '.tif'];
    cy5_filename = [experiment_path '/IMAGES/RAW/' cy5_name '/SC_' filenum '.tif'];
    cy3_filename = [experiment_path '/IMAGES/RAW/' cy3_name '/SC_' filenum '.tif'];
    txred_filename = [experiment_path '/IMAGES/RAW/' txred_name '/SC_' filenum '.tif'];
    
    fret_img = imread(fret_filename);
    cy5_img = imread(cy5_filename);
    cy3_img = imread(cy3_filename);
    txred_img = imread(txred_filename);
    
    color = cat(3, uint16(double(cy5_img).*4), uint16(double(cy3_img).*4), uint16(double(txred_img).*4));
    
    if(display == 1)
        figure, imagesc(color);
        title(['Cycles ' fret_name ' - ' txred_name]);
    end

    if(save_flag == 1)
        savefilename = [experiment_path '/QC/qc_colorfluor_' fret_name '-' txred_name];
        saveas(gcf, savefilename, 'bmp');
    end

    image = color;
