Blending/Transparency

I am trying to create a watch face, where some objects (drawn by dc.drawLine(), dc.fillPolygon() etc.) should be dimmed in active mode when some other indicators are drawn at the top of the screen. To do this, I tried the following:

//  draw the background objects here

dc.setColor(Graphics.createColor(128,0,0,0),Graphics.COLOR_TRANSPARENT);
dc.fillCircle(originX,originY,radius);
// draw the top widgets/indicators here
However, the circle is completely opaque with no transparency/blending with the background whatsoever. I tried different values for the Alpha channel as well as for the RGB, but nothing helps.The behaviour is identical on the watch (Epix 2 gen) and in simulator.