Schema design for products with redundant values so I was looking some design schemes for storing a Product's quantity of a certain color and variant sizes, @Gilbert Le Blanc gives the perfect scheme for me as answered in this question, and the scheme goes as follows:

Product table.

Product

  id    product    
------ ------------
   0    Nike Shirt


Color table

Color

  id    color   
------  -------
   0    black    
   1    white    
   2    blue 


Size table

Size

  id   size 
------ -----
   0    XS
   1    S
   2    M
   3    L
   4    XL
   5    XXL 


Stock table

Stock

  id    product       color    size   quantity
---------------------------------------------
   0        0           0        2       5
   1        0           1        3      10
   2        0           2        2       2
   3        0           2        4       3


This works perfectly well, my issue is: some times a product(e.g. black and white patterned T-shirt) can be categorized as black as well as white!! so we will end up with multiple records in Stock table for the same product! -see tables below for more clearance-

Product

  id    product    
------ ------------
   0    patterned T-Shirt

Color

  id    color   
------  -------
   0    black    
   1    white 

Stock

  id    product       color    size   quantity
---------------------------------------------
   0        0           0        2       5
   1        0           1        2       5


This will causes table Stock to be inaccurate in terms of quantity, I need the product to have more than one color if need for sorting purposes in the UI(user-end/Front-end) and I also want to keep track of the quantity of each color along with the sizes.

I am thinking of creating a separate table that includes the product along with all colors that it can be categorized in. this table will be meant for sorting purposes only. this is a great solution except that it will require more data-entry.

Is there any other way around?!
Add to the color table 'black,white' as this is predominately a stock control system.

This comma separation can be handled in the UI to display in a friendly way.