<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def html_table_color(row, item, color=(0, 0, 0)):
 """ Return background color of each cell of table. :param row: row dictionary :type row : dict :param item: cell number :type item : int :param color : input color :type color : tuple :return: background color as list [R,G,B] """

    result = [0, 0, 0]
    color_list = color_check(color)
    max_color = max(color_list)
    back_color_index = 255 - int((item / (sum(list(row.values())) + 1)) * 255)
    for i in range(3):
        result[i] = back_color_index - (max_color - color_list[i])
        if result[i] < 0:
            result[i] = 0
    return result