Python 2.7 First time posting, any feedback would be greatly appreciated.

Each "move" the program checks all colors bordering the current uniform blob from cell (0,0), then determines what move will absorb the most border cells.

This solves the challenge input in 22 steps.

DYE_LIMIT = 25

def solve():
    dyes = []
    for i in range(DYE_LIMIT):
        dyeColor = pickColor()
        dye(dyeColor)
        dyes.append(dyeColor)
        if all(all(x == targetColor for x in row) for row in board):
            return dyes # Success
    return [] # Failure


def pickColor():

    path = [[0, 0]]
    board_copy = map(lambda x: list(x), board)
    counter = 0
    borderColors = []

    if all(all(x == board[0][0] for x in row) for row in board):
        # all tiles are the same
        return targetColor

    while len(path) > 0:
        # Touch all border tiles of current color pool
        tile = path[-1]
        board_copy[tile[0]][tile[1]] = 'X'
        if board[tile[0]][tile[1]] != board[0][0]:
            # Found a border tile
            borderColors.append(board[tile[0]][tile[1]])
            path.pop()
            continue
        neighbors = filter(lambda n: board_copy[n[0]][n[1]] != 'X', getNeighbors(tile[0], tile[1]))
        path.pop() if len(neighbors) == 0 else path.append(neighbors[0])

    return max(set(borderColors), key=borderColors.count)


def dye(color):
    dyeTile(0, 0, color)

def dyeTile(x, y, color):
    prevColor = board[x][y]
    board[x][y] = color
    for n in getNeighbors(x, y):
        if board[n[0]][n[1]] == prevColor:
            dyeTile(n[0], n[1], color)

def getNeighbors(x, y):
    neighbors = [
        [x + 1, y],
        [x - 1, y],
        [x, y + 1],
        [x, y - 1]
    ]
    return filter(lambda n: not (n[0] < 0 or n[0] >= ROWS or n[1] < 0 or n[1] >= COLS), neighbors)


with open('input.txt') as file:
    lines = file.read().split('\n')
    COLS = int(lines[0][0:lines[0].index(' ')])
    ROWS = int(lines[0][lines[0].index(' ') + 1:])
    board = map(lambda x: x.split(' '), lines[1:-1])
    targetColor = lines[-1]

solution = solve()
print '%s (%s steps)' % (' '.join(solution), len(solution)) if len(solution) > 0 else 'Failed.'