  We present the Technicolor Dawn simulations, a suite of cosmological
radiation-hydrodynamic simulations of the first 1.2 billion years. By modeling
a spatially-inhomogeneous UVB on-the-fly with 24 frequencies and resolving dark
matter halos down to $10^8 M_\odot$ within 12 $h^{-1}$ Mpc volumes, our
simulations unify observations of the intergalactic and circumgalactic media,
galaxies, and reionization into a common framework. The only empirically-tuned
parameter, the fraction $f_{\mathrm{esc,gal}}(z)$ of ionizing photons that
escape the interstellar medium, is adjusted to match observations of the
Lyman-$\alpha$ forest and the cosmic microwave background. With this single
calibration, our simulations reproduce the history of reionization; the stellar
mass-star formation rate relation of galaxies; the number density and
metallicity of damped Lyman-$\alpha$ absorbers (DLAs) at $z\sim5$; the
abundance of weak metal absorbers; the ultraviolet background (UVB) amplitude;
and the Lyman-$\alpha$ flux power spectrum at $z=5.4$. The galaxy stellar mass
and UV luminosity functions are underproduced by $\leq2\times$, suggesting an
overly vigorous feedback model. The mean transmission in the Lyman-$\alpha$
forest is underproduced at $z<6$, indicating tension between measurements of
the UVB amplitude and Lyman-$\alpha$ transmission. The observed SiIV column
density distribution is reasonably well-reproduced ($\sim 1\sigma$ low). By
contrast, CIV remains significantly underproduced despite being boosted by an
intense $>4$ Ryd UVB. Solving this problem by increasing metal yields would
overproduce both weak absorbers and DLA metallicities. Instead, the observed
strength of high-ionization emission from high-redshift galaxies and absorption
from their environments suggest that the ionizing flux from conventional
stellar population models is too soft.
