Brake fluid question

[SDOliner@aol.com]

Going over a friend's recently purchased Bugeye race car, which has not been 
driven for quite some time.

The PO told him that he used silicone brake fluid in the brakes. I dipped my 
finger in the master and the fluid is purple, so my guess is that this is 
silicone.
There is no clutch pedal pressure, and no fluid in that master. I am guess 
that there is still some in the line. Before topping up the master, how can we 
be sre if this  is also silicone?

David Oliner