Which is correct?

This is a sample: it was made up in three seconds.

This is a sample: It was made up in three seconds.

Also, how many spaces should go between the colon and the next word? I was thinking two, since the clause after the colon is independent, but I'm not sure. Help please!

3 answers

If the sample is a complete sentence, the capital will be better. However, I would suggest putting the sample within quote marks.

This is a sample: "It was made up in three seconds."

The older standard was two spaces after colons and periods, but since computerization, newer standards indicate only one. I decided to change to the newer, more current, standard.

I hope this helps. Thanks for asking.
Thanks!
You're welcome!