Take the tour ×  I'm making a poster (using baposter) where I
wish to include some microscopy images. To make the fluorescent
signals stand out better, I changed the background of that cell
to "pitchblack", which I have defined as   I've also tried this
with   However, with my microscopy images in the foreground, I
find out that "black" isn't really black: enter image
description here  The baposterclass brings xcolor and tikz along
for the ride, so I'm assuming my color issue is with those
packages. So my question is, how I can make the "black" of the
background frame black enough to match the background of these
images?  Full code of the frame:  \headerbox{Preliminary
Images}{name=prelim,column=2,row=0,boxColorOne=pitchblack}{
\parbox[t]{0.25\textwidth}{\scriptsize\color{white}
Representative volume renderings of HeLa cells imaged using
TALEs against the $\beta$-globin locus. Signals are
approximately 0.3$\mu$m in diameter.}} & \imagetop{\includegraph
ics[width=0.3\textwidth]{dataimages/5_02_volume_view.jpg}}