Color pins: which color space is better?

[mikemeister_admin]

Hi,
Is there general rule of thumb which color space to use when applying color pins? My guess is that the best color space for color pins would be LAB, because in LAB color changes are better localized than in RGB. Am I right?

[-default]

Actually, it's the other way around, depending if by localized you mean restricted to a certain color range or brightness value.

Lab will remove a color cast with a neutral or pin - or add one - uniformly to the entire image of brightness values, potentially affecting all colors, unless you restrict the effect by using a careful curve shape.  Typically, only one pin may be used in Lab mode, in addition to the shadow and highlight pins.  As you might expect, this effect is very useful when the entire image has a uniform cast that affects light and dark areas equally.

RGB allows, and may require more pins, provided you take care to spread them evenly along the r, g, and b curves.  You also have the ability to pin different brightness values in the image, with the most common example being removal of blue shadows, without adding yellow to the brighter parts of the image.

CMYK, and HSB also have their places in the color correction scheme of things.
http://curvemeister.com/support/curvemeister3/help/Wizard/CSMatrix.htm