I have a 220v outlet. Can I make up a male 220v plug that splits the two hots into two separate 110v standard female plugs? Obviously I would also split the neutral ground wires to each 110v pigtail.

Obviously I would also split the neutral ground wires to each 110v pigtail.
There is no neutral in a 240V outlet.

What is the 240v outlet for?

It's located in an art gallery. On very rare occasions they require a 220v outlet, but more often than not they need a couple 110v outlets. They end up just running extension cords across the floors or up an over stuff. So they are trying to avoid creating trip hazards or climbing on things to get the cords off the ground. My first line of thought was to just convert it to a 110v outlet by replacing the current double 50amp to a single 20amp and designating the red hot as the new white neutral, but they still need the 220v outlet on occasion. And due to cost limitations, they didn't want to run a completely separate 110v line. And "obviously" I wasn't thinking straight regarding the neutral wire at the outlet... long day. Just last week I installed a sub panel for my hot tub which is where I ran the 4 wires from the main to the sub and then hard wired the hot tub past the sub panel breaker. Add to the fact I travelled with the circus for 13 years and out there I've seen some wild contraptions one of which was a 220v male plug with two separate lines splitting off into two 110v female outlets. So any thoughts on the art gallery issue?

Unless you are a licensed electrician, Do Not Do This Work!

Next, by code, Neutral must be Gray or White. It cannot be any other color, not can you re-task the red wire to be the Neutral.

To do what you want, you would need to run at least one Neutral and create a Multiwire branch circuit

However, because this is a Public Gathering Place you have to be licensed. You are flat out not allowed.