Define symbol characteristics. INTERPOL= specifies a cubic regression analysis with confidence limits for mean predicted values. VALUE=, HEIGHT=, and CV= specify a plot symbol, size, and color. CI=, CO=, and WIDTH= specify colors and a thickness for the interpolation and confidence-limits lines. 
symbol1 interpol=rcclm95
       value=diamond
       height=3
       cv=red
       ci=blue
       co=green
       width=2;