Can any sound based imaging device see in color, and if so how does that work?

Yes, it’s impossible. Color is a property of light only. Ultrasound images can be rendered in so-called false colors, however, to help distinguish (for example) blood flow velocities or tissue densities or other properties of the image as a visualization aid.

Sound is mechanical vibrations in a medium while color is a property of light which is an electromagnetic vibration requiring no medium. So, I don’t think sound waves can be used to identify color. Sonar simply works on the sound waves hitting a mass and rebounding to its source. We can only, at the most, create a monochromatic outline of the target object using sonar

+ and therefore, your color-detecting device should also be based on electromagnetic waves, not on sound.

Cannot see in colour.

What @gasman and @krrazypassions says is technically correct. However, like any good engineer, when somebody says “that’s impossible” I immediately try to think of ways to bend the laws of nature to accomplish the goal.

I would think that different tissue densities are more reflective of certain frequency bands than others, thus giving them a spectral signature. That being the case, I see no reason why one wouldn’t be able to produce a multi-frequency sonic imaging device that would be able to recognize the spectral signatures of various tissue types (and depths) and render them in differentiated colors. Sure it would be “false” color, but then again, so is any color image you see on a computer screen regardless of the source. Even images from cameras are digitized and then re-constructed for your viewing pleasure.

So… should I apply for a patent?

it might take several sonicscans at multiple places, frequencies, and amplitudes but,
yes. i think you can by determining materials with known color, and although difficult i think directly calculated conversions could be made as well, with know or unknown substances