When I sing Star of the County Down (slow ballad style, not that mess by the Pogues) I usually replace "brown" colleen with"sweet" colleen... I have found that many songs whose lyrics refere to a brown girl just as frequently mean the color of her hair as of her skin (unlike "dark girl" in Lakes of Pontchartrain, in which she was indeed Creole and dark-skinned); just as "fair" frequently means "pretty. but also refers to pale skin (fair complexion) and, most often, blonde hair...pale, white skin was considered a desirable feature, all the more so if tinged with "blood red" cheeks...classical Northern Celtic colouring. Also, as mentioned before, pale skin was a feature of a woman who probably did not work outdoors and was thus a "lady" as opposed to a milkmaid... so is that "orange" girl a redhead?