I’ve run into this exact snag when migrating Pine Script code from V2 to V4—let’s break down what’s going wrong and how to fix it quickly.

The Root Cause #

Your error comes from a breaking change in how Pine Script handles color definitions between versions:

• In V2, you could use the color() function with 1 or 2 arguments (like color(color.red) or color(color.red, 50)) to define base colors or semi-transparent ones.
• In V4, this syntax was retired. Instead:
  • Native color constants like color.red are already valid color values—you don’t need to wrap them in an extra color() call.
  • To create a color with transparency, you must use the color.new() function (note: the second argument here is transparency, where 0 = fully opaque and 100 = fully transparent).

Fixed Code #

Swap your original line with this corrected version:

colors = cond1 ? color.red : cond2 ? color.new(color.aqua, 50) : color.new(color.red, 50)

Why This Works #

• We remove the redundant color() wrapper around color.red (since it’s already a valid color value in V4).
• We use color.new() for the semi-transparent colors, which matches V4’s required API syntax.
• This eliminates the "too many arguments" error because we’re now using the function signatures that V4 expects.

内容的提问来源于stack exchange，提问作者Fernando Caldas