Thanks for the question. If the missing color is one of the heather options, this may be due due to limited supplier inventory. We will have intermittent availability for heather t-shirts through December. You may still select heathers as a color, however they may not always be available as buying options. If you have any further questions about this specific design or detail page you can also send an email to firstname.lastname@example.org and they will be able to help you with more information.