Regular expression to find a lowercase letter followed by an uppercase

Question

I have difficulty using Regular Expression (Grep) in TextWrangler to find occurrences of lowercase letter followed by uppercase. For example:

This announcement meansStudents are welcome.

In fact, I want to split the occurrence by adding a colon so that it becomes means: Students

I have tried:

[a-z][A-Z]

But this expression does not work in TextWrangler.

*EDIT: here are the exact contexts in which the occurrences appear (I mean only with these font colors).*

<font color =#48B700>  - Stột jlăm wẻ baOne hundred and three<br></font>

<font color =#C0C0C0>     »» Qzống pguộc lyời ba yghìm fảy dyổiTo live a life full of vicissitudes, to live a life marked by ups and downs<br></font>

"baOne" and "dyổiTo" must be "ba: One" and "dyổi: To" 

Could anyone help? Many thanks.

Answer 1

I do believe (don't have TextWrangler at hand though) that you need to search for ([a-z])([A-Z]) and replace it with: \1: \2

Hope this helps.