I want to create a gray scale color layer. Is it possible to create it by using Photoshop filter shader? If it is, can anyone please tell me the way? It will be very helpful for me.
To create adjustable greyscale layer, follow these steps:
Layer >
    Duplicate Layer >
              New Adjustment Layer >
                        Hue/Saturation >
                               DeSat >
                                     (When done) Merge Layer
For more control:
Layer >
   New Adjustment Layer >
          Black & White.
You can tweak every color channel in grayscale. Very cool.
For FABULOUS toning of B/W images with a little less work than B/W layer. (This is my secret. Guard it with your life.)
Layer >
      New Adjustment Layer >
            Hue/Saturation >
                 Blend Mode Color
