We are rather inexperienced gardeners, can anyone please suggest some either bedding or perennial plants that will give us some winter colour. Also we have an area down the side of the garden that is in partial shade and tends to be rather dry, what sort of plants (preferably perennial) would like these conditions. A mixture of short and taller plants would be nice. There are mature trees present, are these pssibly kiiling stuff off, a lot of what we put in struggles to survive. Hydrangeas seem OK We live n Soth Devon, so the weather s not too harsh

This is a massive ask, which is probably why no-one has replied. Perennials die back either completely or to low foliage in the winter. Some exceptions, which have interesting winter foliage are any of the heucheras
and evergreen (not deciduous) ferns. For winter colour shrubs are better - try cornus (dogwood) Sibirica which has bright red stems and would give some height. Winter pansies will give some colour. Perennials that flower early in the year - hellebores (prefer shade) and pulmaneria. Early spring bulbs like crocuses and then daffodils and narcissi are good value.
Trees will dry the soil and give shade but not kill things. Gardens take a long time - try to get some structure with shrubs and small trees first. You can always move perennials around if they turn out to be in the wrong place later.
Oh, and try to get some horse manure or mushroom compost to dig in before you start planting. If you Google any of the above you will find yourself on other gardening and plant nursery sites and will get other ideas.
Good luck!