Colore e geometria. Un modello geodetico del colore per la preselezione delle varianti cromatiche del progetto.

The design of color clashes into two problems; the correct definition of colors and their true representation. A preliminary comparison of color combination seems to be important in the design choice, because the overall effect is more relevant than clarification of the exact value of hues, in respect of which you could yet accept the variable degree of approximation. Therefore, the usefulness of new auxiliary tools development, to allow a display of color choices and their homologous combinations, could be interfaced with the measuring-production-representation of shades. According to color theories, which refer to a wide variety of shapes, a topologically flexible model is able to suit different assumptions and it could be applicable for fabric, wallpaper and tiles design, including interior and urban design. The hypothesis referred to the realization of digital color-solid, allowing quick display of equivalent color combinations, throughout the rotation of some radial alidades, whose direction shows different shade with similar harmony. This requires identifying a regular solid, which to apply the colour symmetry, then proceeding with a geodesic tessellation with the smallest deformation among the different tiles of the tessellation pattern. The solid that best meets this requirement is the octahedron, whose 6 vertices allow to place in a prominent position the four psychological primaries (red, green, yellow and blue) and the two achromatic colors (black and white). The geodesic projection of the tessellation on the sphere allows a - quite- regular layout of all intermediate shades. The choice to replicate the application of tessellation pattern of the same generative algorithm is due to the need to minimize the tiles deformations. This would be lower starting from a solid with a higher number of faces. The pattern allows you to display the selected combination of hue on continuous surface of the sphere. The different colors obtained by mixing two components, both along the diameter of the stereographic projection of the tetrahedrons’ edges, on the face there are the nuances of three blending colors, in the center of which are the intermediate colors between the colors of each vertex. The generative tessellation allows you to change from time to time the number of dowels - then of colors- depending on the difference wanted between contiguous colors. In this way, the arrangement of colors on the surface of the sphere, which is symmetric around its center, allows to "measure" equivalent combinations, by the rotation within the space, by a number of choices of alidades integral between them, either of a regular shape of two or three dimensions inserted into the sphere.