Chemicals that form coloured complexes with Pb2+
In the old book from Hopkin and Williams, Organic Reagents for Mineral Analysis. London (1933), the following information can be found in the Chapter "Diphenylthiocarbazone, or Dithizone". 

Diphenylthiocarbazone is a black powder, insoluble in water, but soluble in organic solvants, giving green solutions. Its main application is its reaction with lead. Lead ions produce a red color to its CCl4 solution. To 10 mL Lead aqueous solution, 1 mL KCN 10%, and two drops of ammonia are added. Add 2 mL of a dilute solution of diphenylthiocarbazone in CCl4 (50 mg/L). Stir. A reddish color must appear if the sample contains 0.001 mg Pb. A similar color appears without lead, due to the solubility of the reagent in CCl4. Addition of KCN removes totally any excess of reagent in the aqueous phase.

The only drawback about this method is the necessity to use KCN, which is forbidden today. I have found in the same book a small article about benzidine, where they say that lead solutions give a blue color when mixed with benzidine, if a solution 0,05% benzidine in acetic acid 10% is used.

Lead can also be detected and quantitatively determined by 8-hydroxyquinolein. But the book mentions only the following bibliographic  references : 
V. Marsson, L. Haase, Ueber die Bestimmung des Bleis mit Hilfe von o-Oxychinolein, Chem. Ztg, 52, 993, (1928)
V. Hovorka, Sur le dosage du plomb au moyen d'ortho-oxyquinoléine, Coll. Czech. Chem. Comm, 9, 191 (1937)