[Delta Tango]

If I understood correctly

Spoiler:

Most unlucky decision on the color would be brown, so asuming you decided on brown socks and are extremely unlucky, you'd take out all black and brown socks before getting the second brown one, so 10 + 8 (black + blue) + 2 brown ones = 20

edit:

Spoiler:

After reading the above spoiler:
It seems I misunderstood you. I thought you wanted some specific colour.