If you want all-year interest, Amelanchier has pretty white blossom in April, and leaves with autumn colour. Or a good evergreen is Nandina (Heavenly Bamboo), whose leaves have red tinges any time of year.

Not sure about what tree/shrub you describe, perhaps a Cherry tree? Cercis is very attractive in spring, as is Ornamental Cherry and even Hawthorn. Hawthorn is actually a lovely tree in its own right, we just seem to think of it as a dull hedge plant rather than an attractive tree in its own right.

How about a Cornus kousa? Beautiful shape with drooping branches as they age and lovely pink or creamy white flowers for weeks in early summer. Could the pink/red cone tree be a Sumach (Rhus typhina)? This tends to sucker and can be a nuisance near paths and lawns.

Yes I was thinking of the Rhus Sumach Volunteer, a nice size though and you can prune it easily, it does have gorgeous autumn colour too.

Maybe one of the flowering crabapples (Malus species & hybrids)?

Do you mean a red flowered horse chestnut? it fits your description but would get much too big for your site - and there is also a disease of horse chestnuts going around. All the above suggestions would be lovely - how to choose??

Ahh!!!, thankyou.
I checked the internet for pics. of a red horse chestnut tree and it fits exactly! You're right, it's too big for a garden but at least i know what it is.