Can anyone explain thread-shed step 19?

I was able to figure out everything up to #18, however I can’t figure out how to work on #19.

  1. Great, now we have a list thread_sold_split that contains an entry with the color of every thread sold today.

Define a function called color_count that takes one argument, color. The function should iterate through thread_sold_split and count the number of times the item is equal to argument, color. Then, it should return this count.

  1. Test your new function by running color_count('white').

Your function should return 28.

here is my code.

for color in thread_sold:
if “&” not in color:

def color_count(color):
count = 0
for thread in thread_sold_split:
for c in thread:
if c == color:
count +=1
return count

why is my output 22 instead of 26 ??? can anyone explain?