What would i use to green up citrus leaves that are a little yellow

If the citrus leaves are yellow with green veins, they may be suffering from an iron deficiency. To help correct this, apply Yates Iron Chelate to the foliage. Reapply every 2-4 weeks, if required.

For more product information: https://www.yates.com.au/product/garden-fertilisers/speciality-fertilisers/yates-iron-chelate