How far can we push chemical self-assembly? This is one of the 25 biggest questions science is facing over the next quarter century, as reported by the Science journal in 2005. The idea of self-assembly is to fabricate synthetic structures or materials from the bottom-up. Up to date a huge class of distinct structures was successfully demonstrated to be fabricated by self-assembly. One important scientific area that exerts the ideas of self-assembly arose from the fusion of the fields of colloidal nanochemistry and nanooptics. There, the focus is on the fabrication of bottom-up nanophotonic structures with a tailored optical response. Very interesting are self-assembled metamaterials (MMs). They promise to widen the possibilities on how to control the propagation of light to an extraordinary degree. Concerning self-assembled MMs the precise spatial arrangement of its unit cells across larger dimensions is not possible in most cases; leading essentially to amorphous structures. Such self-assembled MMs require novel analytical means to describe their optical properties and innovative designs of functional elements that possess a desired near- and far-field response. The first goal of this thesis is the introduction and development of a feasible theoretical description of amorphous MMs. Once the theory is established the second goal is on experimental realizations of self-assembled MMs. Therefore, the focus of this thesis is on self-assembled MMs and the question on how far they can be pushed to obtain artificial materials with an extraordinary optical response.