TypeError: string indices must be integers

[thecoziest]

Error:
TypeError: string indices must be integers

What does this error mean?

I thought I would've fixed... by adding this

int(numbers[color])

in

while count <= 11:
        for color, value in band_values.items():
                if band_values[color] == int(numbers[color]):
                    return numbers

but didn't work & brought up the same error

I'm new to using a dictionary. I'm trying to use one to help me convert the band values to numeric values by searching through a list.

#The first parameter is the two character string return earlier (numbers)
#This function will convert the two characters to a number value &
#return it.
def calculate_raw_value(numbers):

    count = 0

    band_values = {'K':'0', 'N':'1', 'R':'2', 'O':3'', 'Y':4,'G':5,
                   'L':6,'V':7, 'Z':8, 'W':9,
                   }
    

    while count <= 11:
        for color, value in band_values.items():
                if band_values[color] == numbers[color]:
                    return numbers

                elif count <= 9:
                    count = count + 1
                    continue

                elif count == 10:
                    print("ERROR")

Any extra advice/tips would be appreciated.