The Power of Paper and Color

I make this journal mostly as reference for commissioners but also to learn more about my art myself. I think that whether you are familiar with toned paper or not, this journal is pretty interesting for seeing the difference. 
*Updated Jan 1, 2018.

Examples of black and white on white paper:
              

Examples of black and white with ACCENTS of color on white paper (I haven't really done this since 2016):
   

Examples of black and white on tan/gray toned paper:
        

Examples of black and white with ACCENTS of color on tan/gray toned paper (this is another thing I haven't done since 2016):
      
    
I can understand why some people think the cats are full-color drawings because the cats basically look like that, but the only color there is in the pink and the green/yellow eyes. The paper's color made the black and white drawing look more colorful. 

Examples of full-color drawings on tan/gray toned paper:
                    

Examples of full-color drawings on white paper:
    

Examples of full-color drawings on black paper: