&gt; It is grey, always grey.<p>Check out Decorative Concrete:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Decorative_concrete" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Decorative_concrete</a><p><a href="https:&#x2F;&#x2F;www.pinterest.com&#x2F;explore&#x2F;decorative-concrete&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.pinterest.com&#x2F;explore&#x2F;decorative-concrete&#x2F;</a><p>Bonus 1) Translucent Concrete:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Translucent_concrete" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Translucent_concrete</a><p><a href="http:&#x2F;&#x2F;google.com&#x2F;search?tbm=isch&amp;gws_rd=cr&amp;q=translucent+concrete" rel="nofollow">http:&#x2F;&#x2F;google.com&#x2F;search?tbm=isch&amp;gws_rd=cr&amp;q=translucent+co...</a><p>Bonus 2) White Concrete, using Titanium Dioxide admixture, also cleans itself and its environment:<p><a href="http:&#x2F;&#x2F;google.com&#x2F;search?tbm=isch&amp;gws_rd=cr&amp;q=concrete+tio2" rel="nofollow">http:&#x2F;&#x2F;google.com&#x2F;search?tbm=isch&amp;gws_rd=cr&amp;q=concrete+tio2</a><p>Bonus 3) Nanomaterials add a lot of new potential for strength, possibly color, as well as completely new applications.  For instance, carbon nanotubes make concrete slightly electrically conductive, which makes it possible to do easy integrity testing, visible from low voltage current fluctuations near stresses, strains, cracks, etc.  I wish I had more info on a prospective range of applications here.<p>Aside A) Clays (of possibly many colors) can also provide an even cheaper, more readily available, and similarly strong building material.  Sindhi researchers pre-stressed and baked some test beams, and they were just about as strong as comparable concrete.  See Emergence of New Era for Reinforced Baked Clay Construction (Memon, Bhatti, &amp; Ansari):  <a href="http:&#x2F;&#x2F;www.quest.edu.pk&#x2F;rjournals&#x2F;julydec2013&#x2F;julydec2013_1.pdf" rel="nofollow">http:&#x2F;&#x2F;www.quest.edu.pk&#x2F;rjournals&#x2F;julydec2013&#x2F;julydec2013_1....</a>  I sincerely wonder how this ongoing wealth of research on concrete plus many generations old, likely undocumented, skill we have with clay construction could come together.