"färgglad" always makes me wonder.. In German there are two (main) words for it: one is "farbenfroh" which literally translates to "färgglad", but there's also "bunt" which has a slightly different connotation. For me, a "farbenfroh" item has bright, happy colors, I guess, whereas "bunt" just means "many colors". Are there similar alternatives for "colorful" in Swedish as well?
A horribly late reply, but in case you're still wondering: there are the synonyms kulört, brokig, grann, prunkande, färgrik, and possibly more. Actually, I don't think any of them correspond perfectly to bunt, so you could use whichever you prefer, since the meanings are pretty close anyway.
Neither, really. There's an excellent resource on the sj-ljud and other related things by blehg here: https://www.youtube.com/channel/UCUb87YTKOTgnGcAM4toC-6A/videos