How to fill objects on image with adjacent colors?

I am facing troubles with coloring the pink boxes with adjacent colors, so that the image would look more real. My image is this:

So far, I used CV2 package and achieved this:

My code:

up = np.array([151,157,255])
pink_mask = cv2.inRange(img, up, up)
cnts, _ = cv2.findContours(pink_mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
for c in cnts:
    color = tuple(map(int, img[0, 0]))
    cv2.fillPoly(img, pts=[c], color=color)

Here, I filled with the first pixel on the image, as I am not sure how to fill it with the adjacent colors.

We may dilate the mask, and use cv2.inPaint:

import numpy as np
import cv2

img = cv2.imread('input.png')

up = np.array([151,157,255])
pink_mask = cv2.inRange(img, up, up)
#cnts, _ = cv2.findContours(pink_mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
# for c in cnts:
#     color = tuple(map(int, img[0, 0]))
#     cv2.fillPoly(img, pts=[c], color=color)
pink_mask = cv2.dilate(pink_mask, np.ones((3, 3), np.uint8))  # Dilate the mask

img = cv2.inpaint(img, pink_mask, 5, cv2.INPAINT_TELEA)

cv2.imwrite('output.png', img)

Output: