I believe your issue can be remedied by using Nested Styles.
First, define a Character style for the portion of the paragraph that will be unique from the rest of the paragraph (in your case “Text Here:) Then, create a Paragraph style that will be used for the text following “Text Here:”.
Once these styles are defined, choose Drop Caps and Nested Styles in the Paragraph Style Options panel. Create a New Nested Style, choose the newly created Character Style, select “through”, “1”, “End Character Nested Style”.
Return to your document and apply this paragraph style. After each “:”, insert a “End Nested Style Here” (Insert Special Character, Other, end Nested Style Here). NOTE: Until you insert the End Character Nested Style, the entire paragraph will reflect the character style.
If you have multiple occurrences, I would assign a key command or do a search and replace of “Text Here:” inserting the End Character Nested Style in the replace area.
Hope this is an answer to your problem.