470 Ohm Resistor Color Code — Textbook LED History & 47 Family

470 Ω: the “old textbook” LED resistor

Yellow · Violet · Brown · Gold → digits 4 · 7, ×10 → 470 Ω. Yellow and violet are the 47 prefix — same digit pair as 4.7 kΩ (4.7 kΩ guide) but brown vs red multiplier separates 470 Ω from 4700 Ω.

4-band: Yellow · Violet · Brown · Gold → 47 × 10 = 470 Ω (±5%) · 5-band (±1%): Yellow · Violet · Black · Black · Brown → 470 × 1 = 470 Ω (±1%)

Why textbooks used 470 Ω on 5 V (and why kits moved on)

Era	Typical series R	LED current @ 5 V, $V_f≈2V$	Philosophy
1980s–2000s manuals	470 Ω	~6 mA	Very safe, dim, long LED life
Modern Arduino kits	330 Ω / 220 Ω	9–15 mA	Brighter, still within GPIO limits

470 Ω is not wrong — it is conservative. For a panel indicator where brightness doesn't matter, 470 Ω runs cooler and extends LED life.

Brightness snapshot (5 V, red LED)

R	Current	Relative brightness
220 Ω	~13 mA	Bright
330 Ω	~9 mA	Medium
470 Ω	~6 mA	Dim but clear indoors

Yellow–Violet digit mnemonic (47 family)

Both 470 Ω and 4.7 kΩ start with 4 · 7:

Value	3rd/4th multiplier band	Full 4-band
470 Ω	Brown (×10)	Y · V · Brown · Gold
4.7 kΩ	Red (×100)	Y · V · Red · Gold

This confusion doesn't exist on 220 Ω (both reds) or 1 kΩ (brown-black-red).

TTL-era series termination (historical note)

470 Ω appeared in some 5 V logic application notes as a series damping value. Modern CMOS designs use different rules — treat this as historical context, not a universal recipe.

FAQ

470 ohm color code?

Yellow, Violet, Brown, Gold.

Arduino: 470 or 220 Ω?

220 Ω if you want standard brightness; 470 Ω if you want minimum current and cooler operation.

Related guides (different topics)

• 330 Ω color code — 5 V vs 3.3 V supply matrix

• 220 Ω color code — LED brightness vs 330/470 Ω on 5 V

• 1 kΩ color code — divider math & strong pull-ups

• Values hub — pick by application

• How to read any resistor (method)

• Decode bands online