Nathan
Sorry about that! To style a graph, you can do things like this:
from iolite.ui import IolitePlotPyInterface as Plot
from iolite.QtGui import QBrush, QColor, QPen
from iolite.QtCore import Qt
import numpy as np
p = Plot()
g = p.addGraph()
g.setData(np.array([0, 1, 2, 3, 4], dtype=np.float), np.array([0, 1, 2, 3, 4], dtype=np.float))
g.pen = QPen(Qt.red, 3, Qt.DashLine)
g.brush = QBrush(Qt.blue)
g.setScatterStyle('ssDisc', 8, Qt.green, Qt.cyan)
p.replot()
p.show()
p.resize(500, 400)
So the line itself can be styled by setting the g.pen = QPen(...). Here, I've set the color to red, the line width to 3 and the style to dashed. The fill can be controlled by setting a brush. And the marker style is controlled with g.setScatterStyle(...). The options for the first argument can be found here, then it is the marker size, marker pen and marker brush colors.
You can also get rid of the line entirely for a graph by doing g.setLineStyle('lsNone').