Though I like the idea of using large visuals to show portfolio projects, in the case of Public – sometimes the transition from dark – whereas navigation disappears – to light is too much and makes for a poor user experience. The simplicity of the colored squares navigation is ok but the opening empty index space is overwhelming. Important to make sure to pick meaningfully related backgrounds.
Best to keep it within the same color range palette. Something to keep in mind if you intend to use such an approach.