For sealing cracks on a concrete driveway before applying a solvent-based colored concrete sealer, you'll want to use a polyurethane or silicone-based caulk that is specifically labeled as paintable with solvent-based products. Look for products that mention compatibility with concrete and are suitable for exterior use. Some popular options include Sikaflex Concrete Fix or DAP Concrete and Mortar Filler.
It's important to ensure that the caulk is fully cured before applying the sealer, which can take anywhere from 24 hours to a few days depending on the product and environmental conditions. Always check the manufacturer's instructions for specific curing times and application guidelines.
Since you're working with a driveway, consider the temperature and weather conditions when applying both the caulk and the sealer to ensure optimal adhesion and performance.
As a next step, I recommend visiting a local home improvement store or checking online for these products. Additionally, if you're unsure about the application process, getting 2-3 local quotes for professional help on Handyman.com could be beneficial.
— Assisted answer