Optifine causes issues w/ minecolonies. That's the only reason it hasn't been added to the pack.
Install Dallas1117 Custom 1.16 Pack
Step 1
Installing a modpack using the Technic Launcher is easy. If you don't already have the launcher downloaded, visit our download page to get the latest version.
Step 2
Type in the modpack name (Dallas1117 Custom 1.16 Pack) or paste the following url into the search box.
Step 3
Finally, click Install at the bottom right of the launcher after you select Dallas1117 Custom 1.16 Pack from the list on the left. The launcher will handle everything else!