def red_yellow_colourmap(original_col, shade=10):
    """Red colour specification is input and returns
    a red to yellow colour map"""
    col_list = []
    col_list.append(original_col)
    curr_col = original_col
    z = max(original_col) / float(shade)
    for i in range(0, shade - 1):
        new_col = curr_col[0], curr_col[1] + z, curr_col[2]
        col_list.append(new_col)
        curr_col = new_col
    return col_list
