Yes, eCart can handle items with your complex requirements.
but if you are using eCart 5, you will not be able to do this using Cold Fusion, eCart 5 support PHP only.
what is unrealistic is to expect detailed documentation for the database structure needed for your specific requirements. A hammer does not come with blue prints needed to build a house.
for the colors, sizes and border requirements, the optiongroups, options and productoptions table structure of the eCommerce database will work.
for the quantity discounts, you will need to add a column for low and another for the high of each quantity break point.
there are many threads in the forum that talk about implementing quantity discounts, perhaps this one will help: