Isenberg, L., Nissen, M. J. & Marchak, L. C. (1990). Attentional processing and the independence of color and orientation. Journal of Experimental Psychology: Human Perception and Performance, 16(4), 869-878.

Judgments of the color and shape of a stimulus specified by a cue indicating its location demonstrate stochastic independence. Evidence for the independence of color and orientation was obtained when the cue followed stimulus offset immediately, the cue followed stimulus offset by 2 s, and when either a central or peripheral precue focused attention on the cued stimulus at the time of its presentation. It appears that an object's volor and orientation are represented independently even following the attentional focusing thought to support feature integration.