The collection includes a single style of trainer in three colourways and eight pieces of clothing that take all take their colours from the flags of East African countries.
"Africa is a beautiful continent and the origin of civilisation," said Williams, about the decision to draw on the flags of East African countries.
Solar Hu comprises two tank tops, t-shirts, running tights, and pairs of shorts. The trainers come in three colourways, and each pair is sold with two additional pairs of laces in shades that compliment the particular design.
The vamp – the section of the shoe that covers the front of the foot – is embroidered with graphic versions of the Hu logo, and there are suede details that add texture to the shoe.
"Hu is short for human – human being, human race, humankind," said Williams when the first Hu collection launched in 2016. "But Hu, itself is also a reference to colour. As human beings, we all have a colour. We all look different, we all speak different languages, but we’re all connected."
The trainers come in shades of yellow, red, green, orange, white, black and cyan – colours inspired by the flags. The clothing follows the same colour scheme, with patterned fabric details in elaborate zig-zag patterns that decorate the shorts and tights.
Williams' previous collection for the brand under the Hu label celebrated tennis, but Solar Hu focuses on running, which the musician describes as "a state of meditation".
The collection also aims to honour the culture of long-distance running in the region, given that many of the best long-distance runners come from East Africa.
"Why not go back to the motherland and take inspiration from such a vivid and rich culture?" asked Williams.
"Why not create a tribute to this incredible sport? Why can’t the shoe that people wear on the street have a performance function?"
Adidas recently launched a vegan version of their Stan Smith trainer in collaboration with fashion designer and animal rights advocate Stella McCartney, which features an illustrated portrait of the designer on the tongue of the left shoe.