Telect offers both Singlemode and Multimode adapter patch plates for use in our fiber panels.  While the physical dimensions of the adapters are the same for Singlemode and Multimode, industry practice is to use different colored adapters for different cable types and connectors.  For example, Singlemode UPC adapters are usually blue where Multimode adapters are usually beige.  This color coding allows field technicians  o quickly identify the type of fiber that is connected to the rear of the adapter patch plate in the panel.  So, as long as you are matching like fiber type to like fiber type (Singlemode to Singlemode or Multimode to Multimode) on the patch plate the color of the adapter would not matter.  However, it is not a recommended practice.