Define the character style with the wanted color other than defined in theparagraph style. Use this character style for the numbers.
Yes. Character styles override the Paragraph styles. Put the main paragraph of text (whether it's 1 line or 10 lines) in a paragraph style.
Then apply a character style to indvidual, letters, words, phrases, or numbers where you want them.
How are you creating your Index Page? There may be a way to automate the entire thing - in fact I'm sure there is.
If you are using InDesign's indexing tools, you can set your page numbers to the character style. If you are creating the index some other way, nested styles will allow you to apply the character style to the page number as a part of the paragraph style.
I am using Indesign CS3. I have created text boxes and I am flowing the text through the document as it has 35 pages.
It will be a header in bold like this (part 1 would be in a different colour as would the number at the end) the second part not in bold.
Part 1 Introduction
1.1 xxxxxxxxxxxxxxxx p1-4
1.2 xxxxxxxxxxxxxxxx p4-5
(part 1 would be in a different colour as would the number at the end)
There are a number of sections with quite a number of points and steps.
Use nested styles. This will do it automatically.