Could you define, please, what you mean by color smear? I'll offer a couple of pointers, but without knowing exactly the effect you're after, I might miss.
A directional blur applied only to the channel you want to smear can give you that look of a video signal with a red that's too saturated. In the Common Controls tab, uncheck everything but the channel you want to affect. Maybe mask it with a LumaKeyer set to saturation to only hit the really saturated areas. You could do something similar with a Transform node—either translating or scaling (or both) only one channel might give you something like you want.
Or for that sort of imprecise color of 4:0:0 footage, which is also sometimes called smearing, you could conver to YUV using a Color Space node, scale it down and then scale it back up, combine the original Y (R) with the munged-up U and V (G and B) channels in a Channel Boolean, then back to RGB.
If you're looking for more of a paint smearing kind of thing, there is a smear mode in the Paint tool.