When an indicator plots multiple values, you select each separately, and set properties from the toolbar -- or double-click and use a dialog box. You MAY have to click on an empty area of the chart, before selecting another set of values to change.

Personally, it's better to NOT plot indicator-on-indicator -- it's easier to just rewrite as an all-in-one.

Unfortunately, the code you posted seems garbled, so I'm not sure what you're trying to do, exactly; you should be able to convert the PSAR to an independent indicator, rather than having to overlay it -- just put in the formula for Price OSC, which should be in the manual, online formula library, or a quick search should turn it up.

>>2. Overlay a (DUAL) coloured PSAR on top of this.

If you are trying to use the PSAR on an indicator, you may be out of luck. I think this is dependent on the CLOSE, and if memory serves, can NOT be written in the Metastock Formula Language; it would have to be DLL.

OTOH, if you merely want to combine the status of PSAR with the PriceOsc, that should be doable. Here is the formula, from the Metastock Help file:

{ _PSAR -- your formula, at least what I could make of it }
A:=Input("Step value", 0.001,1,0.018);
B:=Input("Maximum value",0.01,1,0.2);
R:=SAR(A,B);
If(R<C,R,0);
If(R>C,R,0);


{ _PriceOsc -- from Metastock Help }
M1:=Input("MA 1",1,500,10);
M2:=Input("MA 2",1,500,20);
PriceOsc:=(( Mov(C,M1,E) - Mov(C,M2,E) )/Mov(C,M2,E)) * 100;
PriceOsc;


{ _Price Oscillator and PSAR -- combined }
M1:=Input("MA 1",1,500,10);
M2:=Input("MA 2",1,500,20);
PriceOsc:=(( Mov(C,M1,E) - Mov(C,M2,E) )/Mov(C,M2,E)) * 100;

A:=Input("Step value", 0.001,1,0.018);
B:=Input("Maximum value",0.01,1,0.2);
R:=SAR(A,B);

If(R<C,PriceOsc,0); { Green for long }
If(R>C,PriceOsc,0); { Red for short }


FWIW, it might be helpful if you did a screen-capture (Alt-PrtScrn), paste it into Paint, maybe label things a bit, and upload with IMGUR.

Here are the above formulas, plotted on the SPX: