When jump sprinting on redstone, the particles appear like the greyscale texture, rather than red like the particles you get when breaking it.
As redstone is not solid, most of the time when you sprint on it particles of the block below are created, but if you jump while sprinting, redstone particles are created. To see them, make a line of redstone, look down, sprint on it and jump.
Linked issues
is duplicated by 11
MC-7815
Running particles bug
Resolved
MC-12638
Redstone Dust Particles
Resolved
MC-28436
Sprint particles on redstone dust are white, not red
Resolved
MC-31040
the fall particles are grey when falling onto a Carpet with redstone under it
Resolved
MC-46191
Glass particles when flying over or hovering on redstone and or near a lever
Resolved
6 more links
Attachments
Comments 18
Related to MC-418, should be a similar fix.
8 more comments
Can confirm, the situation is caused by the texture of redstone in the terrain.png being grey and having a hard-coded color for it.