These keys will fit the RD-250s, 300s along with those listed below. They are just slightly yellowed and we can not guarantee an exact color match with your existing keys. 

Roland HP-230
Roland HP-700 
Roland HP-800
Roland HP-900 
Roland HP-1000S
Roland HP-1500
Roland HP-1700
Roland HP-1700L
Roland HP-1800 
Roland HP-1900G 
Roland HP-2500S
Roland HP-2500SL
Roland HP-2700
Roland HP-2900G
Roland HP-3000S
Roland HP-3500S 
Roland HP-3700
Roland HP-4000S 
Roland HP-4000SL 
Roland HP-4500S 
Roland HP-5000S
Roland HP-5000SL 
Roland HP-5500S 
Roland HP-5600S 
Roland KR-3000
Roland KR-4500 
Roland KR-5500 
Rhodes MK-80
Rhodes MK-60
Roland RD-250s
Roland RD-300s