### colorBorder 
from typing import *
def f_gold(grid: List[List[int]], row: int, col: int, color: int
) -> List[List[int]]:
    m, n = len(grid), len(grid[0])
    vis = [[False] * n for _ in range(m)]
    def dfs(i, j, color):
        vis[i][j] = True
        old_color = grid[i][j]
        for a, b in [[-1, 0], [1, 0], [0, -1], [0, 1]]:
            x, y = a + i, b + j
            if 0 <= x < m and 0 <= y < n:
                if not vis[x][y]:
                    if grid[x][y] == old_color:
                        dfs(x, y, color)
                    else:
                        grid[i][j] = color
            else:
                grid[i][j] = color
    dfs(row, col, color)
    return grid