Chrysler color codes: solid color = power feed, with tracer = signal. Reading a base + tracer (e.g., DB/WT = dark blue with white tracer) is the FSM wiring diagram convention.
Chrysler-era XJ wiring diagrams use a two-character color code system: base color plus tracer color separated by a slash. Common codes: BK = Black (ground), BR = Brown, DB = Dark Blue, DG = Dark Green, GY = Gray, LB = Light Blue, LG = Light Green, OR = Orange, PK = Pink, RD = Red, TN = Tan, VT = Violet/Purple, WT = White, YL = Yellow. A wire labeled DB/WT in the FSM is dark blue with a white stripe. Power feeds (constant 12V): always Red base. Ignition switched 12V: typically Pink. Ground: always Black base. Sensors and signals: varied, but typically a non-red non-black base color. The XJ has a few specific harness conventions: PCM signal grounds run to a star ground point near the firewall passenger side; fuel pump power is DB/WT in most years; HVAC blower switched circuits are RD/WT, RD/YL, etc., stepped from low to high. The factory wiring diagram in the FSM is invaluable for any electrical work; print the relevant page when chasing a circuit.
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.