You can paint the cabinets a light color.
You could lighten the cupboards, paint the walls lighter, light fixtures that would light the room better, there are many options depending on what you could do to lighten up the kitchen. You could even put rope type lights under the upper cupboards and lower cupboards. If the floor is dark, perhaps lighten it also would help, or use lighter rugs on the floor that you can wash.
Scrub well - replace the hardware. Lighten up your walls - light color throw rugs.