Definitely don't go with too much Black Patent!
If you need to adjust your color afterwards you can always use Sinamar:
SINAMAR® is produced solely from our roasted malt CARAFA® SPECIAL, according to the strict German "Reinheitsgebot" (purity-law). This law allows the brewer to use only the following four ingredients:
MALT - HOPS - YEAST - WATER
To get the characteristic color and extract, SINAMAR® is carefully evaporated in a vacuum process, finely filtered and canisters and containers of different sizes are filled directly at 158°F - 167°F (70 - 75°C).
Due to this special treatment the taste of SINAMAR® is less bitter.
SINAMAR® causes no turbidity and remains pH stable.
According to federal regulations, SINAMAR® does not need to be labeled with a so-called E-number (European Community Number). A declaration as malt extract, barley malt extract or roasted malt extract is sufficient.
SINAMAR® is perfectly suited for coloring foods such as: baked goods, beer, non-alcoholic drinks, spirits, pharmaceutical products and tea etc. SINAMAR® is gluten free.
In order to raise the color of 1 hl beer though 1 EBC, 14 gr. of SINAMAR® is required.
Unopened containers have a 1 year shelf-life.
Once opened, contents should be used immediately and stored cool.