During the check availability process with Google Ad Manager, if a required placement is unavailable, a yellow check mark appears if partial quantity is available, and a red check mark if none is available (C). This visual indicator helps users quickly understand the availability status of placements and make informed decisions about adjusting campaign plans or exploring alternative options.References:
https://help.salesforce.com/articleView?id=sf.dmp_advertising_sales_check_availability.htm
https://www.salesforce.com/products/media-cloud/overview/