You may do it this way:
Select all three shapes in front and the square and Pathfinder>Minus front.
Make sure all of your pieces are unfilled and unstroked and in front on the colored square. Select them all and from the Object menu choose Compound Path>Make. Place it over any background and the "R" will be that color.
That didn't work? Any other suggestions?
You may have accomplished a Compound Path. Select it, look at the Appearance Palette (Illustrator's poor excuse for an object inspector) and see what kind of object it is.
Illustrator is not nearly as intelligent as FreeHand regarding path direction. You may very well have a Compound path, but some of the subpaths need their winding direction corrected. DirectSelect (white pointer) one of the subpaths that did not become a hole, and try toggling the Reverse Path icons in the Attributes palette.
The best way is to have a pre-Intel Mac set up just for running Freehand.
This is because Illustrator is a total piece of sh*t. I first encountered Illustrator at Version 2 (88) and was impressed when Adobe introduced Version 3 which featured the all-new pen tool for drawing Bezier curves. Unfortunately they haven't improved anything after this point.
I'm trying to make a compound path out of three paths (the letter B) and Illustrator is just too dumb to cope with more than three paths as a compound unit. Two paths is fine. Three, no way (and yes, all paths are closed). Which is why, in the end, it was back to Freehand to do in ten seconds what I had been attempting to do for 45 minutes.
The interface is buggy, the menus are obscure, drawing and moving elements on screen is an exercise in hit-and-miss. There is absolutely NOTHING about Illfrustrator that I like. Putting it in simplest terms, working in Illfrustrator like going back to 1992.
In the end the only way Adobe could force people to buy their crap software was to eliminate the competition. Which they did. Very successfully.
"Give me Freehand or give me death!"
Thanks, JET... this was the perfect solution for me. Just reversed the knockout parts and magically they, ur... knocked out.
I also miss FreeHand!!!