The color of Taiwan politics, plus u versus ü Pinyin sounds

I had a recent conversation with a native Chinese speaker about political groups in Taiwan.  The group which leans toward unification with China is "blue", while the other group preferring formal or informal independence from China is "green".

She mentioned lán yíng, whose first word I knew must be 藍 (blue), but I had to ask what the second word was.  She explained that it was "camp" -- much as it is used in English when discussing politics.  So her original reference was to 藍營.

Camping, I said, according to my recollection, was lù yíng (露營). She then mentioned lǜ yíng (double dots over the u), which made me think that I had misremembered the vowel in the first syllable in camping, and I (mistakenly) switched to lǜ yíng as the pronunciation for "camping". She then clarified that she had said lǜ yíng (綠營), referring to the green camp.

While there are surely other common expressions of 2 or more syllables which might be mentioned together where u and ü are both possible as the only difference between corresponding syllables (tones and all other aspects of the letters being the same), I found 綠營 (lǜ yíng) and 露營 (lù yíng) to be an interesting pair.