Thanks for the info. Hopefully this shouldn't make games too hard to make, although I am a bit concerned about how to draw images and sprites in softwares like paint that supports 2, 4, 8, 16 and 24 bit color depths but not 15. I hope it won't make it too hard to convert stuff. Granted, the quality drop shouldn't be as noticeable as someone converting an image from 8 bit to 6 or 7 bits, but I know for certain people quality is extremly important, and they might hate if certain image colors they think as important suddently appeared  in different colors on their TI-Nspire.

Oh well... at least TI finally added colors to their calcs. I'm also glad they opened them to Lua dev (now the next step for them is to not try blocking Ndless anymore)

OOh ok I see now. I guess that might be good then. And yeah it shouldn't be a big issue. After all, it's several thousands of colors on a tiny screen. Pixels are very small and the CX screen smaller than the regular TI-Nspire screen, so it's not like a few dithered sprites will hinder quality too much.

The screen itself is 16 bit color, but the Ti.image format can only handle 15 bit color (with the 1 bit alpha).

I spy TF2!
Also great job implementing IM for more formats.

Like the 84, or slower?

It's usually slow with colored images drawn on the whole screen (i.e. all the gc:drawImage() functions at the end draw on every pixel on the screen). A Mario-like platformer that utilizes every single pixel of the screen might not be very playable (Edit: unless there are a lot of transparent pixels). Those are the current results of years and years of rigorous scientific experiments on the Nspire using Lua.

Hmm that looks nice

You should probably move those in another thread, though, so more people see it and it's less off-topic.

Also are monochrome images the same format as grayscale/color ones? I wonder what causes the slowdown otherwise?