Apparently, there is no way to manually change the particle effects from the AreaEffectCloud entity through the throwing of a Lingering Potion (or I am just bad at commands). This makes it so it is impossible to change the particle colour unless mixed potion effects are used. The AreaEffectCloud entity is also virtually impossible to target if multiple potions of different variety are thrown and mapmakers want to label them.

/give @p lingering_potion 1 0 {CustomPotionEffects:[{Id:20,Amplifier:6,Duration:600}],tag:{Color:146142,Radius:5}}