HP 39GS grayscale and stuff

[Elitniy CalcLover]

So one time I have got my hands on an engineering calculator, it broke pretty soon (it was very old and from a noname company) it ignited my interest in advanced calcs, just like that after searching and reading lots of pages of information about lots of models, I decided I need one - the best option was the cheapest graphing calculator - HP 39GS famous for surplus ones for 2100 roubles (~21$). Place an order on aliexpress, wait a long month and there you have it - cheapest graphing calculator that can still pack a punch. It arrived approximately half of a year back, right before the summer holidays, so I did not had a chance to mess with it fully (i do think the problem was that it didn`t include a printed instruction, it would be much easier to read the printed one, rather then a digital copy on the computer or a phone) now when academic year has started again, it gave me the chance to explore this calc while doing homework, or trying to understand classwork, I can tell that this was 21$ well spent, although russian study program doesn`t include or allow any calculator to do the work, it is really nice to have that piece of technology to explore math concepts on it (and of course games!).

Now the question i wrote this thread about - grayscale. I tried to find this info but didn`t found any - does the HP 39GS have grayscale, if not can i fix this somehow? The hpcalc.org site shows that grayscale games are compatible with 39/40 series, but on my 39gs pixels that should be grayscale just flick on and off, this makes it impossible to play some of the best games like HPWorms, I can send the video if needed.
Im having trouble to find the manuals for programming and development software for 39gs cause most of the official HP sites regarding older calcs then Prime shutted down, if anyone has a copy of ADK39 - send me one.
Also it would be nice to have some advice, like what aplets to download to expand 39gs functionality, any key combinations that would be interesting.
Thanks in advance.