Changing the Color of D and E

Stolen from my previous post, this is the purpose of this post.

Bank vault systems that have a tactile number pad for pin entry are vulnerable to misuse by a thief. Thieves can use cameras, themselves, or even other people to view the pattern that a 4 digit pin makes when entered; therefore they do not need to know the actual value of your pin, just the sequence of button presses that will allow for entry into the system. To overcome this fatal flaw, a touchscreen display that has a number pad GUI may be used, with the keys being shuffled every time the pin is entered whether it is correct or not.

Im trying to make this user friendly so I would like the values D and E to be colored Red to make them easy to locate, however when I tried adapting the code, it would change the color of all of the values. Does anyone know a work around? Any and all help is appreciated. The following is my code:

import tkinter as tk
import random

def code(position):
global pin
b = buttons[position]
value = b['text']

if value == 'D':
    # remove last element from `pin`
    pin = pin[:-1]
    # remove all from `entry` and put new `pin`
    e.delete('0', 'end')
    e.insert('end', pin)

elif value == 'E':
    # check pin
    if pin == "3529":
        print("PIN OK")
    else:
        print("PIN ERROR!")
        # clear pin
        pin = ''
        e.delete('0', 'end')
else:
    # add number to `pin`
    pin += value
    # add number to `entry`
    e.insert('end', value)

print("Current:", pin)

shuffle_buttons()

def shuffle_buttons():
for key in keys:
    random.shuffle(key)
random.shuffle(keys)
for y, row in enumerate(keys):
    for x, key in enumerate(row):
        b = buttons[(x, y)]
        b['text'] = key                

# --- main ---

# keypad description

keys = [
['1', '2', '3'],
['4', '5', '6'],
['7', '8', '9'],
['D', '0', 'E'],
]

buttons = {}

# create global variable 
pin = '' # empty string

# init
root = tk.Tk()

# create `entry` to display `pin`
e = tk.Entry(root, justify='right')
e.grid(row=0, column=0, columnspan=3, ipady=5)

# create `buttons` using `keys
for y, row in enumerate(keys):
    for x, key in enumerate(row):
        position  = (x, y)
        b = tk.Button(root, text= key, command= lambda val=position: code(val))
        b.grid(row=y+1, column=x, ipadx=20, ipady=20)

        buttons[position] = b

shuffle_buttons()

root.mainloop()