樓上的答案里的鏈接A Color Picker Pen That Reproduces Any Color.，是這麼個東西：
就是說，確實有這樣的產品，但不是問題里的那個只處在概念階段的韓國貨。這個Scribble Color Picker Pen，是已經公布在7月底全球發售了。
而該產品沒有違背我們熟知的RGB加色、CMYK減色原理，使用的是CMYK墨水，而不是RGB墨水。不過，奇葩的是，除了CMYK四色，Scribble Color Picker Pen還有白色墨水——看到參數里的那個White么？
至於為什麼有白色墨水，我英文不好，大家自己看吧：
Why white ink?
Why do they add white ink, you may ask? My desktop printer doesn"t use white. The printing press that printed my copy of the Edmund Optics Swimsuit Issue used CMYK inks, but no white. Why would this fabulous pen need white?
There are two reasons why white is used when mixing stuff to get colors. White flood-coat is often used on clear packaging to back up the standard inks. This provides opacity that is not found in the substrate or the inks. Much like writing with a red pen on black paper, the ink wouldn"t show up without a base of white. But, I suspect that this isn"t the reason that the engineers of the Scribble Pen added the complexity of white ink.
If I want to print a pink highlight with an ink jet printer or on a web offset press, the approach is pretty simple. Don"t put much ink down. Just a dribble of magenta ink, or just a sprinkling of tiny halftone dots. But if you are searching for that same color to paint your wall, you need a different solution. You need the same volume of paint, just less color. When mixing up a can of paint, the paint mixologist first reaches for a can of white base.
You see something similar when you can look at the Pantone fan deck, which includes the recipe for each of the thousand-plus colors of ink. Pantone 217, for example, calls for 1 part of rubine red ink and 31 parts of something called "transparent white". Transparent white is unpigmented ink, and would look transparent (not actually white) if printed by itself.
The Scribblers may actually be using ink that contains white pigment (titanium dioxide or zinc oxide, maybe). But I think it"s more likely that it is more likely that they use a transparent white ink. It would be neat to write on black paper with a pen, but I would guess that it is nearly impossible to get any sort of decent opacity with the amount of ink dispensed with a pen. Think about how much "ink" that a WhiteOut dispenser spits out.
雖說掃描儀和噴墨印表機的體積比這支筆大很多倍，然而，掃描儀的LED燈和感光器的體積很小，噴墨印表機只是靠墨盒裡的噴嘴進行噴墨的。我個人理解，只要把這些零件簡化，再加上主控晶元、電池、墨水，組合在一起，就能實現這支筆所宣稱的功能了。
針對光源色環境色什麼的問題，從官網給的視頻看，那玩意取色的大頭是一個平面，摁在物體表面，基本不透光，然後由大頭裡面的一個LED燈照明，所以杜絕了環境光線的影響…… 同樣從官網給的視頻來看，那玩意輸出的小頭有兩個頭，一個是電磁頭，用在觸摸屏上和數位板上（可是這兩種完全不是一個原理吧！），一個是噴墨頭，用在紙上。 偏色是肯定會偏色的，所以只是一個玩具。 官網在此Scribble – color without limits ，我相當懷疑有沒有做出成品來。製作團隊原本說今年7月上市，結果又宣布延期，然後還在鼓勵別人捐款給他們
