Hola Winn,
I am including a work flow for you, which you will not need to do any programming in ArcPad. This will allow you to Categories your data in ArcMap by a unique field. Then you will be able to check the data out for ArcPad, and then you will be able to collect new feature and they will reflect the proper marker and color. My one suggestion with this work flow is to keep the symbol markers simple to properly reflect in ArcPad from ArcMap on the check out. Please let us know if you have any further questions or comments. Gracias, Winn!
Work flow:
1. In ArcMap categories your data by the field you want to change as you add a new feature and change the symbol marker
2. Then check your data out for disconnect editing upon current extent
3. Move your project to the device
4. Collect a new feature and populate the unique value field in ArcPad, you will then see how the marker will reflect the correct symbol and color