Need a Dax function to look for a specific text value and return another text value in a new column

Hi,

Trying to create a lookup value in live data (cube) and create a new reference column/dax function with text values.

e.g. if 'Red' then 'Danger' 

However, when I am trying to select the text column name, it will not, I can only select the numeric column types. 

Also, I am not able to  use string functions such as 'Evaluate', 'Contains string' etc. Substitue only works with a measure value

The Cube is locked, so I am unable to create my own internal tables, or upload an excel file as a reference table.

Can someone please let me know how I might get this to work please?

Thanks