If you discount based on card colors, this is the default setup in Rose. There's nothing you need to do except to set the default card color for new inventory within the Locations/Discounts Module, which can be found within the Hamburger Menu.
Setup your default Take-In card color for your location and Save. If you do this monthly or bi-weekly, set yourself a reminder to change this in Rose when the time comes to do so.
When you are ready to discount a particular color, set the discount % and click save changes. Once saved, then find the color in the drop down menu below the save button and click Send to Square. This will send all inventory attached to that color with the new discounted price to Square, so that they ring up at the new price at the register. Depending on the number of items in inventory this can take from a few minutes to a couple hours. This depends on how busy Square is at the time so we suggest that card color discount changes be done the night before you want to put them on sale.