My advice is not to rely on any colors rendered on a computer or any other image. It's impossible to select a color from a screen, a print image, or even the way a color looks in someone else's home or a room in your own home. What I see on my monitor is probably not what you see on yours.

Color is a function of light, and the way the light hits a surface will determine how it appears. To make matters worse, the color can change depending on the time of day.

If you are having trouble selecting a color, you might retain the services of a color expert to help you along the way. There will be many Houzzers posting here giving you advice, but you may end up going down a rabbit hole of color frustration. There's no shortcut to selecting color, you need to test them with your own eyes. A color expert can help you narrow down the choices so you're not buying can after can with no luck. Also consider buying samples of the colors you like to see them on your house.

Good luck with your project.

I agree there is only one way to choose color and that is seeing it in your light with all the things around it.. Even color experts need to be at your home

is SW Stunning Shade too purple for you?... just a darker version of your chosen Slate Purple.

why not just use your SW Slate Violet for the columns? in the bright west light, it will look lighter than the side exterior siding without introducting another color paint to the mix.

Is there a reason you decided to do the front only with the tabby finish?

It reminds me of the houses in New England with shakes on the front and standard siding on the sides/back OR brick on the front and siding on the sides/back.

Why not just Stunning Shade ?

I will definitely try the Stunning Shade for the gables! Thank you. I must have skipped it initially thinking it might be too dark. For the columns, I do think the Slate Violet is too dark, having seen it in the western sun. (I am not just relying on screens and chips -- I have been painting samples on large boards and moving them around the house to see them from different times of day and from different angles.)

thank you so much!! I am so happy there is SOME HOPE for the columns -- I tried SW Ponder yesterday and it was hideously pink. Also tried SW Mysterious Gray and it became an almost icy blue. the Grapy also looks very promising for the gables. I will report back :) thank you again <3

I think you are over thinking 2 tones of the same color is all you should be doing in fact I would do one .

Paints are made of pigments added to white. You can create a darker version of Slate Violet by upping the black pigment or decreasing the white. Most paint stores mix the paints there are happy to mix to your specifications. Admittedly, I've only lightened paint colors, never tried to darken them, but I'd imagine the same technique would work. Be sure to get a sample of your custom pigment before deciding on it.

I hear the advice about simply lightening or darkening one color, whcih I may try. I have heard a couple different things about this approach: simply saying - mix this at 80%, for instance does not mean that you get the same result or that this is performed in the same way every time.... (some may increase decrease the black to make it lighter, or some may make each if the included pigments lighter).... and that anyway this approach doesn't the color lands in the same tone. so it would require a lot of different color tests to end up with the 3 perfect shades. Am i thinking about this incorrectly?

By the way today I am testing grapy and stunning shade :)

Tested:

for the columns: SW mysterious gray and BM stormy monday

for the sides of the house: BM Stone and SW Slate Violet

for the gables: SW stunning shade and valspar urban pulse

Here is what 4:30 pm FL sun does to colors:

There are thousands of colors from a multitude of paint manufacturers, so I find it unnecessary to tweak colors. You are correct that simply saying "lighten/darken this color x%" doesn't guarantee that you'll actually get the same color, just lightened or darkened. Sometimes it changes in a way you did not anticipate. Some pros here are very good at tweaking colors, but for homeowners it can send you down a rabbit hole and a very expensive one at that.

Am i thinking about this incorrectly?

You are thinking about it exactly right.

The fact that there are not that many paint colors in the range you are looking is another clue.

The question to ask is, if it were so easy to move colors light/darker and muted/stronger in this range of colors, why don't those colors exist as stock?

So, if the paint brands aren't making a range of colors lighter than Stunning Shade, what are the odds that adjusting the formula will work.

We simply don't know. The only way to find out is to buy a quart and see what you get.