We introduce a notion of Dyck paths with coloured ascents. For several ways of colouring, when the set of colours is itself some class of lattice paths, we establish bijections between sets of such paths and other combinatorial structures, such as non-crossing trees, dissections of a convex polygon, etc. In some cases enumeration gives new expression for sequences enumerating these structures. Keywords. Dyck paths, non-crossing graphs, dissections of polygon by diagonals. 2000 Mathematics Subject Classification: 05A05, 05A15.