The code below changes the first line. However, there are no spaces between words and therefore, the justification is also off. You can even leave the first parameter empty and you get the same results.
Am I missing something?
\starttext
\TreatFirstLine {\sc} {} {} {}
The combined color and font effect is also possible,
although one must be careful in using macros that accumulate
grouping, but the commands used here are pretty save in that
respect.
\stoptext
Thanks,
Bart