Using mesh renderers for emitters with shaders which do not have the _Color property (i.e. Particles/Alpha Blended) throws an error in the console.

Repro steps:
1. Open ParticleBug scene from attached project.
2. Select Particle System in Hierarchy and under the Shape module enable "Use Mesh Colors".
3. Observe error in Console.

Expected outcome: Use mesh colors to account for all _Color values provided in Unity's build-in shaders (i.e. _Color, _TintColor, etc.)

Notes:
- not a regression; new-ish feature, happens in 5.3.2f1
- while not all names used for color can be accounted for, perhaps covering just the ones used in Unity's build-in shaders would suffice.
- workaround is to simply name one's color property in the shader used "_Color".