You can set graph element properties using set_int() or set_float() method. Some of the examples are:
gl.set_float('x.from', 1.5)
gl.set_int('x.showgrids',1)
gl.set_int('plot1.color', 4)
You can refer to the webpage for those properties:
https://www.originlab.com/doc/LabTalk/ref/Layer-Axis-obj
https://www.originlab.com/doc/LabTalk/ref/Layer-Plotn-obj
James