gcas.add(gca);
gca.setStart(StylesFactory.eINSTANCE.createGradientColoredLocation());
IGaService gaService = Graphiti.getGaService();
final Color startColor = gaService.manageColor(diagram, ColorUtil.getRedFromHex(colorStart)
, ColorUtil.getGreenFromHex(colorStart)
, ColorUtil.getBlueFromHex(colorStart));
gca.getStart().setColor(startColor);
// gca.getStart().setColor(StylesFactory.eINSTANCE.createColor());
// gca.getStart().getColor().setBlue(ColorUtil.getBlueFromHex(colorStart));
// gca.getStart().getColor().setGreen(ColorUtil.getGreenFromHex(colorStart));
// gca.getStart().getColor().setRed(ColorUtil.getRedFromHex(colorStart));
gca.getStart().setLocationType(locationTypeStart);
gca.getStart().setLocationValue(locationValueStart);
gca.setEnd(StylesFactory.eINSTANCE.createGradientColoredLocation());
final Color endColor = gaService.manageColor(diagram, ColorUtil.getRedFromHex(colorEnd)
, ColorUtil.getGreenFromHex(colorEnd)
, ColorUtil.getBlueFromHex(colorEnd));
gca.getEnd().setColor(endColor);
gca.getEnd().setLocationType(locationTypeEnd);