Colour Matching/Mixing Paint

[Davidm]

I have some garden fencing and a shed painted with Cuprinol Garden Shades (Ducksback) in a now obsolete colour - Holly. I have had to replace some of the fencing and have bought a 5L can of the same paint in Forest Green (the darkest green that they now have except Moss, which hasn't got enough green in it) but it's too light and SWMBO doesn't like it. I'd thought of getting some black and try mixing it**, but would like to get some idea of quantities and what it would look like.

I wonder if there's some way of using a photo editing program (I use Corel Paint Shop Pro) to test the effect of adding black to green, but I don't understand how to do this, as black is an absence of colour. Any suggestions how I can do this?

** I've asked decorator centres (Dulux and Brewers) and they've said that they can't do this, their machine can't handle it - the colour, not the mixing of this type of paint.

[Dave Plowman (News)]

You'd need a pretty sophisticated prog to do this as light and paint (reflected light) work in different ways. Also the design and line up of your monitor would have to be spot on.

Can you take a flake etc of the paint to one of those places who claim to match it?

[Chris Hogg]

The simplest way is to get half a dozen or so small plastic pots (yoghurt or cottage cheese pots are ideal), and mix by the teaspoon (green:black 3:1, 2:1, 1:1, 1:2, 1:3 or whatever) stir well and paint small patches with a cheap fine brush, or even apply with a cotton bud. Use smaller increments when you've decided roughly what's closest to what Her Majesty wants.

[The Natural Philosopher]

CMYK colour specification might allow you to test.

Sounds total bollocks to me

[Davidm]

I asked both DDC and Brewsters this, they said not, dunno why, maybe they just couldn't be bothered. A couple of years ago DDC colour matched a dark green wall tile to produce some gloss paint for my front door, so don't understand why Cuprinol is any different.

[DJC]

Screen colours are nothing like paint colours, it's not just the difference between additive and subtractive mixing, paint pigments react differently when combined. All the colour mixing to order systems use different sets of pigments and base colours.

I had this problem earlier this month when painting my garage and shed. None of the standard range of Osmo country colours were suitable (the choice is either too bright or several shades of grey) (and I was not paying +50% for RAL shades to order). I mixed my own by mixing a small quantity to test and then upscaling to the same ratio when decided.

In the course of which I discoved some interesting reading on colour theory:

[tabbypurr]

Take a sample and add black sounds good - if that's the direction you want the colour to go in. You'll find though that black is an exceptionally strong colour, you'll probably only need the tiniest amount.

Getting spot-on matches with this sort of approach probably won't happen. So change batch on a corner or different walls etc.

NT

[Vir Campestris]

We were repainting our house (rendered) and wanted to change the colour back to something more traditional. 6 patches later we picked the best, not ideal, and went ahead.

The real paint turned out not to be very close to the sample pot :(

Luckily a lot closer to what we had in mind :)

Andy

[Mike Clarke]

I recently tried to get some dark masonry paint to match a wall that was painted several years ago. The trade paint supplier said that they couldn't mix that colour any more. The machine was capable of producing the colour but the software wouldn't permit it for exterior paints. Apparently the manufacturers consider some of the darker colours are not sufficiently resistant to fading so won't supply them for outdoor use.