Diffuse and Transparent/Diffuse shaders on mobile platform

I want to know just how much overhead and problem do diffuse and transparent diffuse shaders cause on mobile platform. I mean for particle and spell effects I’m using grayscaled templates and then change color using diffuse color. It works and doesn’t seem to make problems, but I just feel uneasy seeing that warning about considering to use mobile opt shaders.

Thanks in advance

The warning written by you takes place to be. But it isn’t critical for a mobile platform. If you want to get rid of warning, you should write the shader, being based on the standard. So, at first it is necessary to download a set of standard shaders(built-in) with Unity. Then to open the necessary mobile shader and to add in it one more variable of color.