Program "Colors Builder" is intended for creation of harmonious color circuits for web-site and formation of sets of palettes for web-design. Opportunities of a choice of primary colour from a palette of colors are included in the program: using Windows dialogue, from scale of the colors generated by the program and "manual" input hexadecimal HTML codes of color. The program visually allows to select color scales from chosen (primary) colour with smooth transition from one color to another and to determine their six-digit hexadecimal codes. In the program the opportunity of preservation of the received color circuits is stipulated as: TXT a file and its viewing in the text editor; HTML a file and its viewing in the browser; copying of codes of colors in a clipboard. The program will be useful to web-designers and to programmers. It has intuitive - understandable interface, without installation.