When breaking a mob head the particle effects that come off it are those of soul sand. Also when breaking a beacon block the particles that come off it is those of a diamond block. When throwing a splash potion the particles that come off it is those of a normal potion.
When breaking any of the following, particles also are displayed wrong, they don't display the particle of a block broken but instead of a different similar block:
piston [extended: true] skull brewing_stand [has_bottle: false] enchanting_table anvil [damage: >0] flower_pot (no dirt particles, only show top particles) tripwire_hook
For chest, trapped_chest, ender_chest, water, lava, standing_sign, wall_sign, standing_banner, wall_banner and skull the reason is that they use special renderer (this is also the reason for MC-64634)
Confirmed for 1.10 at least for chest, ender chest and brewing stand, for many I'm not sure, because I partially use the "faithful" texture pack and it's not easy to see. I have custom textures for enchanting table and that seems fixed (produces white particles for mostly white table), also anvil, that's just a bit darker, as the flower pot and probably the tripwire hook.
I don't say that it should fix or cause it, just make it better visible. The correct situation should be that the particle uses the texture of the block. But if the particle's texture is only slightly different, it's hard to see. If you paint the whole block in another colour with a ressource pack, it only makes the difference much more visible.
Confirmed for 1.10.1 for chest, brewing stand, enchanting table and flower pot. Others are unclear from my tests. It's apparent that there isn't a general solution here either. I'll do a big test for everything again in 1.11.
No, that would make it even worse, because they would have to add the texture manually for every block. I'm pretty sure that it currently directly uses the block's texture. I don't know why it still fails in so many cases.
The Cauldron particle changed to blue when they fixed the "Water in cauldron isn't tinted" bug in 18w20b (https://minecraft.gamepedia.com/18w20b), this then broke the cauldron break particle, you notice it a lot more when using a resource pack.
This means the cauldron break particle is using the water tint colour.
Confirmed in 1.16-pre3. Ender chests, beacons, flower ports, signs, and banners seem to be fixed as of 1.16-pre3. However, I'm unsure if chests (including trapped chests) display the correct particles: they show Oak plank particles.
I'm pretty sure MC-2614 is not actually WAI, but rather "won't fix" or even just "won't fix for now", meaning "postponed". Back then that resolution was misused a lot for those cases.
Can confirm.