Comment 14 for bug 692582

@JazzyNico - maybe too late, but here are some of my thoughts:

Maybe the dialog needs two tabs [1]:
a) use color / opacity from object
b) set marker style independently

In the first tab, stroke and fill style (color, opacity) are taken from the selected object (mimicking style inheritance):
- solid marker (fill & stroke use object stroke color)
- filled marker (fill & stroke use object fill & stroke color)
- inverted marker (fill & stroke use swapped object fill & stroke color)
optionally pick opacity from object (for both fill and stroke)

In the second tab, markers can be colored independently:
- stroke color with alpha (color chooser or list of presets)
- fill color with alpha (color chooser or list of presets)
optionally no fill / no stroke

[1] similar to the latest version of the 'Guide creator' <http://code.google.com/p/inkscape-guides-creator/>, or the extension 'Replace fonts', each tab applies a different command (i.e. the settings don't add up between tabs).