Fix color picking accuracy

[superhighfives]

Summary

• Store picked colors in sRGB instead of the display's ICC profile color space, eliminating lossy color space conversions that caused 1–3 value drift per channel
• Normalize overlay color to sRGB so the overlay and stored color always match
• Remove the color space observer that mutated stored colors on preference change — the user's color space preference now only affects display/copy output

Fixes #187

Test plan

• Pick a known color (e.g. a solid #0E1829 block in Figma) and verify Pika reports the exact hex value
• Test with different color space preferences (sRGB, Display P3, Adobe RGB) — picking the same color should always yield the same stored value
• Verify the color overlay shows the same value as the main UI
• Test undo/redo after picking — colors should round-trip without drift
• Test picking from NSColorPanel — should also store accurately

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR aims to fix small per-channel drift in picked colors by normalizing/storing picked colors in sRGB (rather than the active display/ICC profile), and by ensuring the on-screen overlay reflects the same normalized color.

Changes:

• Normalize eyedropper stored colors to sRGB during initialization and when setting colors from sampling / system color picker.
• Normalize the overlay’s displayed color/text to sRGB so overlay and stored value align.
• Remove the Defaults color-space observer that previously mutated stored colors on preference changes.

Comments suppressed due to low confidence (1)

Pika/Services/Eyedroppers.swift:154

• In start(), the overlay is rendered from normalizedColor (sRGB), but the stored value is set via self.set(selectedColor), which converts again inside set(_:). To guarantee the overlay text/color and the stored color match exactly (and avoid any double-conversion rounding drift), pass the already-normalized sRGB color into set(_:) instead.

                    let normalizedColor = selectedColor.usingColorSpace(.sRGB)!

                    if Defaults[.showColorOverlay] {
                        let colorText = normalizedColor.toFormat(
                            format: Defaults[.colorFormat], style: Defaults[.copyFormat]
                        )
                        let cursorPosition = NSEvent.mouseLocation
                        self.overlayWindow.show(
                            colorText: colorText,
                            pickedColor: normalizedColor,
                            nearCursor: cursorPosition,
                            duration: Defaults[.colorOverlayDuration]
                        )
                    }

                    self.set(selectedColor)

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

You can also share your feedback on Copilot code review. Take the survey.