[spark_skins] enabled and disabled Halo ColorPicker control with Gumbo skins look inconsistent

Steps to reproduce:
1. Compile and run attached MXML file.
2. Toggle the FxCheckBox control to enable/disable the ColorPicker control.

Actual Results:
The disabled ColorPicker control draws an extra 1px stroke around the color chip, causing the color chip to look slightly larger when the ColorPicker is disabled.

Expected Results:
The color chip should look the same, regardless of whether the ColorPicker control is enabled or disabled.

Workaround (if any):
n/a