smart casual dress code

I have to dress 'smart casual' for my work exp. and these dress codes are just unnecessarily cofusing... what you've just described seems sufficient. smart casual is basically just half a step (emphasis on half) down from being a suited up businessman/woman. For trousers, they dont have to be tailored, as long as they dont look like denim. A waistcoat might look a little too formal, a blazer should be just fine.
hope this helps

What colour trouser would you suggest and also for the blazer?
Dark?

I'm surprised that you have to wear smart casual to a party, but anyway I had to wear it for work experience as well.
I wore black trousers and a plain casual top. I didn't feel I needed a blazer because my manager told me it was quite warm where I was working, but you can wear a blazer or cardigan if you want

darks and neutrals are all good, but you can have a bit of colour if you want, so long as it's not too bright/bold (so no neon greens, but a light blue is okay)

Would grey do,
I dont want a mainstream dark colour if u get me?