- "All sweet things are fluids" implies that all sweet things belong to the fluid category.
- "Some fluids are coloured things" implies that some but not all fluids belong to the coloured category.
- Combining these, we can conclude:
- Some sweet things are coloured things (B)
- Some sweet things are fluids (C)
- Some fluids are sweet things (D)
\(⇒\) \boxed{\text{B, C and D only}}