It's chromatic if it can play every note of every scale. Like a chromatic harmonica. Not like a stock D/G box, that can play every note in the diatonic scales of D and G, and a couple of crucial accidentals to boot, but not every note of every scale. A B/C box is chromatic. The fully-chromatic instruments I've mentioned can play every note of every scale but that does not mean they can play in every key with equal ease. I doubt whether that applies to most "chromatic" instruments. You can play every note of every scale on a C chromatic harmonica but you cannot effectively play Irish music on it. Which implies that you can't play in every key with equal ease. Etcetera. You have an instrument that plays diatonic scales and some, but not all, accidentals and you need a name that does not include the word "chromatic." Or maybe you don't need a name!