Forums Scripts & Popups wait for an input

I wish to have the following type of script
/sf1 /say "The Troll Alert System now issues a <input a color name> Alert, repeat there is a <repeat the colors name> Alert!


So how do I make the this work so it waits for me to type in Fuscia or Orange or whatever before sending it to the chat room?
As always, Please and thank you.

Something like this:

/sf1/say The Troll Alert System now issues a $$?="Enter Colour Alert" Alert, repeat there is a $! Alert!