I would like to increase the brightness/vividness of the purple color in the following image:

[![enter image description here](https://i.stack.imgur.com/vf1Gn.png)](https://i.stack.imgur.com/vf1Gn.png)

Here is the color palette

[![enter image description here](https://i.stack.imgur.com/JbDeN.png)](https://i.stack.imgur.com/JbDeN.png)

Here is what I tried: but this increases the brightness of the whole image:

```
def increase_brightness(img, value=20):
    hsv = cv2.cvtColor(img, cv2.COLOR_RGB2HSV)
    h, s, v = cv2.split(hsv)

    lim = 255 - value
    v[v > lim] = 255
    v[v <= lim] += value

    final_hsv = cv2.merge((h, s, v))
    img = cv2.cvtColor(final_hsv, cv2.COLOR_HSV2BGR)
    plt.imsave('img_new.png', img)

    return img

```

how to create a mask to modify brightness only the pixels in the input that corresponds to purple?