CSS variables error

[Maria Jose Esteve]

Hello,
I am trying to use "variables" in my default CSS but not succeeding, when 
compiling I get an error:
Error: Unexpected exception 'java.util.NoSuchElementException' at 
org.antlr.runtime.misc.LookaheadStream.LB:159

I have tried declaring them in ": root", ".global" and ".Application" but I 
always get the same error.
For example:

  .global {
    --pricolordark: #2196F3;
    --pricolorlight: #BBDEFA;
  }
  .jewel.topappbar .topBarAppHeader {
    background: val(--pricolordark);
  }

I have found a thread from the old FlexJS forum where Harb and Greg comment the 
same error but with the "calc" function. It seems that the solution was to 
create an external css that would not go into the compilation process but this 
does not work here.
any ideas? Do you know if they can be used?

Thanks.

Hiedra.