In reply to Patrick Laffey.

Thanks for bringing this to my attention. The defaults changed along the way. You will need to add the statement:

class graph / attrpriority='none';

to your template definition. When you get a chance modify your TEMPLATE definition so it looks like this:

proc template;
define style mystyle;
parent=styles.htmlblue;
class graph / attrpriority='none';
class GraphData1 /
contrastcolor=orange linestyle=1 markersymbol='circlefilled';
class GraphData2 /
contrastcolor=purple linestyle=1 markersymbol='trianglefilled';
end;
run;