Graphical Equations for Excel (alpha)

Thanks. Another style issue I'd like thoughts on. What do we do with functions names, i.e

=IF(A1>10,"Big","Little")

I'm converting this into

Notice, I'm converting all uppercase excel function names to lower case. Now with functions like SIN, COS, TAN etc, they are more usually written in maths notation in lower case. However should I make everything lower case, or everything uppercase.

Perhaps I should write functions in a different color also - green perhaps, i.e.