Hi,
if I understood you correctly, you want to change a property of nodes
already selected?
If this is correct, then:
1. Activate the "visualization" tab on the left side.
2. Set "category" to "mapping"
3. Set "type" to "color" (if you want to change the node color)
4. Set "property" to "node color" (see 3)
5. Set attribut to "uniform", if you want to set the color manually
6. Set "method" to "color table"
7. Down in the "value|color" table, click the colored field and pick a
color from the palette
8. Ensure the "restrict to selection" is checked (=color just the
selected node)
9. Click "visualize". Done!
HTH,
Kimmo