The following four years Colombo was active as a painter and sculptor of the abstract Expressionism and exhibited his works with other members in Milano, Torino, Verviers, Venice and Brussels.

In 1959, Colombo had to take over the family company, which produced electric appliances, and started to experiment with new construction and production technologies.

Moreover, Colombo produced innovative designs for furniture, lamps, glass, doorknobs, pipes, alarm clocks, and wristwatches.

He created the professional camera Trisystem (1969), the air conditioner Candy (1970), dinnerware for Alitalia (1970; still in use), as well as an ergonomic and engined printing table.

Traditional furniture was replaced by functional elements like the sitting cubes Night-Cell and Central-Living as well as the Kitchen-Box, to create a dynamic, multifunctional living space.

The kitchen-box (1963), on wheels and measuring 90x75x75cm, containing a two-burner stovetop, oven, grill, refrigerator, cutting board, pull-out worktop, and storage for cookbooks, knives, and other tools, has recently been reissued, slightly enlarged (96 cm(h)x107cmx65cm), manufactured by Boffi Spa.

It presented a complete "living-machine," comprising kitchen, wardrobe, bathroom, and sleeping accommodation, on only 28 square meters.