Color
TI BASIC and TI Extended BASIC used the commands CALL SCREEN(C) and CALL COLOR(S,F,B) to change the color of the screen background and of sets of characters.
For CALL COLOR the characters were grouped into sets and every character in a set was changed with one command.
The edge character and the cursor were Character 30 and 31 and in Set 0. Then each following 8 characters were in a set, so that characters 32 to 39 were in Set 1 and 40 to 47 were in set 2 and so on. TI Basic allowed 16 sets, but in Extended Basic only 14 sets were available as the sprites took up required memory.
The difference in the number of character sets available to Basic and Extended Basic caused problems running some TI Basic programs in Extended Basic, but a short VDP utility was developed by users which could be merged into a TI Basic program to enable it to run with Extended Basic (with Expansion Memory).
In Extended BASIC, CALL COLOR could be used to change sprite color - CALL COLOR(SN,SC) and several sprites could be changed in one command - CALL COLOR(SN1,SC1,SN2,SC2,SN3,SC3)
The colors could look very different from one users color tv set to another due to the users choice of tv settings. Even with modern digital monitors the user may still adjust the color balance or temperature. In addition different emulators have used differing color definitions for the TI color set.
Look at the TI Test Card splash screen. The background is cyan, color 8. The boxes across the top are in the order:
7 4 2 12 13 14 16 5 3 14 9 15 6 10 11 7
so that every color is represented.