there's an informal mode of address that conveys the (one-sided, frequently) sense of familiarity, which goes [2nd person singular] [noun in vocative case] [adjective referring to the noun], like panie szanowny (lit. esteemed sir, but the inversion from the adj + noun to noun + adj signals different mode; so “szanowny panie” is formal, “panie szanowny” is shortening distance or expressing annoyance); it can be used, and frequently is, as a phrase that's a personal affectation (e.g. “królu złoty!”, literally “golden majesty”). the affectation is usually rather annoying.

on the other hand “misiu” (vocative case of diminutive word for “bear” or “bear cub” or “teddy bear”) is a common word of endearment.

so “misiu kolorowy” is a bit of a wordplay on both, and should generally convey serious lack of respect and clear annoyance. (i'm guilty of using this from time to time since the times of polish usenet.)

there's an added bonus in that there was a popular child series “miś colargol”, the pronunciation of “colargol” and “kolorowy” are pleasantly alliterative. (now this really shows my age….)