Try this code:
YJMbad1 ;
s a=1
i a<1 q
s a=1
tag ; comment
w $zversion
i a'="" w (a'="")
q
Unless you add at least one space between the < and the 1 on the third line the code colorer seems to treat <1 as the start of an HTML / XML tag, so it colors the remaining code incorrectly.
Add the space to see things as they should be.