halftone cmyk set of overlay backgrounds. four colored blots - cyan, magenta, yellow and black. emulation of raster dot

halftone cmyk cyan magenta yellow black abstract spotted background halftones vector backdrop circles pattern dots dotted retro decoration tone raster design wallpaper concept gradation circle graphic element fabric modern creative geometric artwork round decorative texture print color colour ink dot press blue colorful printer set overlay backgrounds four colored blots black emulation printing