Would I be correct if I were to say that subtle bodies are colorless and shapeless, unlike fleshy bodies?
In my understanding any attempt to use qualifiers (shape or color) or their absence of from the materialistic world to describe subtle bodies (Sukshma Sharira) would be difficult. So, you can say Neti, Neti, not this, not that.
Per Shankaracharya's Tattva Bodha(https://shlokam.org/texts/tattvabodha-verses/),verse 11.1, as part of Avastha Trayam, describes Subtle bodies, composed of Pancha Mahabhutas prior to their undergoing the process as Panchikarana, born of good (or bad) actions of the past, as the instruments or the "abilities" for the experiencing pleasure, pain, etc... Subtle bodies are the counterpart of gross organs that keep the gross body alive, perform all the physiological functions and operate the organs of action and perception. For example, with physical eye as an organ in the gross (Stula) body, "seeing" as the ability can be interpreted as a subtle body.