Limestone is more porous than granite and quartz, however works well in bathrooms and fire surrounds which are less exposed to staining.
Brush away dust, that might be enough to inject some life.
As limestone is a natural stone, and a more porous one, it must be sealed to decrease the chances of staining and scratching. Your stone mason should ensure that their product is correctly sealed before fitting; however it’s always worth double checking yourself. You can then reseal your limestone surface every 1-2 years to really stop the staining.
Clean it with a gentle, surface cleaner, ideally PH neutral. Avoid bleaches and other harsh cleaning chemicals which can lift layers of seal from your granite.