\input luaotfload.sty

\pdfminorversion=5 \pdfcompresslevel=9 \pdfobjcompresslevel=9

\font\testa=file:lmroman10-regular.otf:color=FF0000BB;+liga;+tlig;+trep" at 10pt
\font\testb=file:lmroman10-regular.otf:color=FFFF0099;+liga;+tlig;+trep" at 10pt
\testa \input knuth \par
\testb \input knuth \par
\bye