Final answer:
The observation of three spots on a TLC plate suggests that the compound is impure and contains multiple components.
Step-by-step explanation:
After a thin-layer chromatography (TLC) experiment, if three separate spots were observed on the chromatogram, it can be concluded that the mixture being tested contains multiple components, which likely indicates that the compound is impure. This is because each spot represents a different substance in the sample that has traveled a distinct distance along the TLC plate due to differences in polarity and interaction with the stationary phase. The presence of multiple spots does not necessarily provide information about the volatility or color of the compounds present.