A bit more detail...

 I've been asked for more detail about the colours I showed in the MAC Palette of my favourite watercolours last post. Here is what I like about each of them. I don't for a minute suggest anyone needs all these in their palette - some suit a small or limited palette, others are just fun for a special purpose. Some I only have so I can demonstrate the differences between similar hues. But of the hundreds of watercolours I've tried, these are the ones I think are particularly useful or special. So this is my sample palette for teaching.

While most are Daniel Smith since they are the paints I have been using for over 20 years, there are similar colours and/or pigments available in other brands for some of these, others are DS exclusives. I have made my Ultimate Mixing Set bold, and my favourite 24-colours for my own palette italic (so many are both) 

I usually have an 'extras' palette, even when plein air, in case I want the wonderful properties of one of the Primateks or other pigments. I have said many times - watercolour is not just about the colour - they can be mixed from a very small selection - it's also about the properties of the pigments :-)

The first row.

• Buff titanium DS PW6:1 a granulating and slightly unbleached white opaque watercolour great for urban sketching, sand effects, sandstone, marble and gum trees. This is one of my most used colours.
• Hansa Yellow Light DS PY3 - a very pure and bright cool yellow. I don't use a cool yellow much, but this is a great choice if you want one as it is relatively transparent and mixes beautifully. I have this to demonstrate, and put a cool yellow in my students' palettes.
• Hansa yellow medium DS PY97. I use this as my main yellow. It's a mid or primary yellow, but so much more lightfast than aureolin (PY40). It's a great pair with quinacridone gold.
• New Gamboge DS PY153 This has been reformulated, but I have some old stock. Very similar in hue to Hansa Yellow Deep, with is another excellent choice for a bright warm yellow - a great pair with hansa yellow light.
• Quinacridone Gold DS PO49 I love this slightly neutralised warm yellow as a great mixing gold. It makes wonderful greens with any blue or with phthalo green, and adds a glow to a painting. Only available in DS 15ml tubes, though the mixed hue in the 5ml tubes and sticks is also very pretty.
• Benzimida orange deep PO36 DV. Da Vinci make excellent watercolours, including many in 37ml tubes. This is one of my favourite single pigment oranges. It's very bright, semi transparent and mixes beautifully with blues for neutrals. 
• Trasparent pyrrol orange DS PO71. I love this as a very transparent warm red option. It's a little more tricky to use than pyrrol scarlet, the warm red I recommend, as it has more of a drying shift. But it is gorgeous as an orange wash under red fruit and flowers for more brilliance
• Pyrrol Scarlet DS PR255 This is possibly the most beautiful warm red I've used. Really bright and mixes nicely with yellows to make bright oranges or interesting neutrals with phthlo blue

Second row

• Pyrrol Crimson PR264 DS is a powerful crimson. I love it alone or mixed with phthalo green to make a fantastic range of deep greens, maroons, greys and a rich black.
• Carmine DS. This is one of my favourite primary red options in a limited palette - it is a lovely crimson but also mixes clean oranges and purples. Quin rose is cleaner still, so is another excellent primary red.
• Purple Magenta Schmincke PR122. Daniel Smith have just released a PR122, which I haven't yet tried. It is probably the closest to a primary magenta as found in a CYM palette. It mixes clean purples and clean oranges. However I don't like the basic magenta colour as much as the basic rose colour so I prefer Quinacridone Rose as my purple-mixing red.
• Quinacridone Rose DS PV19. This is another great primary red choice, and the colour I use to mix purples. Transparent and beautiful, is is useful for skin tones, florals, mixing and so on. One of my key mixing colours.
• Imperial Purple DS PV19 + PB29. While this is a very easy purple to mix using palette colours, sometimes it is useful to have a convenient premixed purple and this granulates nicely. As it is made from two basic palette colours, I can always use it without any loss of colour harmony. The alternative PV23 purples are more staining though useful if you don't want granulation.
• Moonglow DS PR177+PG18+PB29. This is a really interesting purple-grey with fantastic granulation. It is gorgeous in the shadow areas of florals and as I don't tend to have viridian in my palette it is a difficult one to mix myself on the go. Not used often, but I do love it.
• Sodilite genuine DS - this is a lovely granulating blue-grey. Similar in hue to my Jane's Grey but even more granulating.
• Indanthrone Blue DS PB60. This is one of the most beautiful rich deep blues. It has a little drying shift but is a powerful deep warm blue option. I use ultramarine more, but this is gorgeous for a night sky or stormclouds.

Third row

• Ultramarine Blue DS PB29. There is also French Ultramarine, which is ever so sligthtly more red and more granulating, but I use the series 1 ultramarine as it mixes perfectly with Burnt Sienna to make my Jane's Grey. This is a basic palette colour for me. Great for skies, for mixing a range of greens or purples, and for use as a lovely non-staining warm blue.
• Cobalt Blue DS PB28. I love this colour, though I won't often use it. I use ultramarine more as it is more on the purple-side so gives a more versatile warm blue. Cobalt is a mid blue - neither warm nor cool - and would be lovely in a limited palette with hansa yellow medium and Quinacridone Rose.
• Phthalo Blue Red Shade DS. I love the way this mixes with Transparent Pyrrol Orange. It can also be the exact colour of the Australian sky. However I tend to recommend the Green Shade for a greater mixing range.
• Cerulean Chromium DS PB36. There is also a cerulean made from PB35 but it is not as strongly pigmented nor as cool. I love this for sketching - with ultramarine you can mix a blue-sky colour for anywhere in the world. Being non-staining, it is easy to lift out the clouds.
• Phthalo Blue Green Shade DS. A powerful, transparent and staining cool blue - excellent mixer and great for glazing. It's a basic palette colour though I tend to use it more for mixing than painted alone.
• Blue Apatite Genuine DS. I really love granulation. I don't use this much, but I enjoy playing with it :-)
• Manganese Blue Old Holland PB33. Though now discontinued, this lovely gentle blue has exquisite granulation. It's perfect for the sparkly shadows of snow in some lights, though not for Australia sadly. I don't use it much but have a little stock of this now difficult to get pigment.
• Cobalt Teal Blue DS. I don't actually paint with this, but have it in this palette to show the difference between it and my preferred Cobatl Turquoise below. It's a gorgeous colour, and I'd take it to New Zealand to paint the colour of the water in the rivers, but it's often just to unrealistic for me.

Fourth row.

• Cobalt Turquoise DS PB36. This is the same pigment as ceruelan chromium and it has the same semi opaque and heavy granulating characteristics. I use this in water, for creating copper effects and for extra granulation. A lovely extra.
• Viridian PG18 DS. This is a much more gentle cool green. It won't mix the powerful blacks you can make with phthalo green, but the granulation is lovely. I don't use it much, but keep it more for comparisons.
• Phthalo Green Blue Shade PG7. This is a colour I don't use alone, and suggest you simply don't when painting from life as it is such an unrealistic green. It's a great mixer though, making spectacular greens with a warm yellow or many of the earth colours.
• Jadeite DS. This is a great alternative to phthalo green if you want more granulation and texture. A lovely colour that changes mood whether applied in a wash or deep masstone.
• Jane's Black PG7 + PR264. This is another custom mix I make to have a rich deep black without using a black pigment. Made from Pyrrol Crimson and Phthalo Green to a neutral deep black.
• Perylene Green PBk31 DS. This is one black pigment that I use. I love this deep shadow colour for the shade between trees, the deep green in foliage and the lovely greens it makes when mixed with yellows. convenience darks save time when painting.
• Undersea Green DS PB29 + PO49. This is an old tube as the new formula is a three-pigment mix, but I find it a very useful green for foliage in Australia and overseas.
• Green Apatite Genuine DS. This is a lovely granulating green, similar to Sap green, that gives surprising results. Fun to play with. (lives in my 'extras' palette)

Fifth row

• blank - the 48th pigment I may add to this set is Potter's Pink. Or perhaps a single pigment granulating violet - I usually mix my purples but PV14, PV15 and PV16 are interesting... though it means moving a lot of colours in the palette...
• Sap Green DS PO49 + PG7. This is another old stock Sap Green (I bought a lot when they were changing the formula) and it is a perfect premix for foliage and leaves throughout the world. Having a convenience 'home green' can really be helpful when painting, especially on location.
• Serpentine Genuine DS. This is a beautiful extra - perfect for a field of grass. I don't use it much, but the lovely specks of brown that appear as it dries are just gorgeous. (Also lives in my 'extras' palette)
• Rich Green Gold DS PY129. A very green-yellow, useful for foliage when the light is shining through the trees. Not an essential colour, but I use it in plain air palettes of 24 colours.
• Yellow Ochre PY43 DS. One of three earth yellows - this will mix great sap greens and is lovely in an earth primary palette. 
• Goethite DS PY43. My most used earth yellow - I love the granulation, and the way it creates sandstone, beaches and other textures with such ease. I mix this with Quinacridone Gold for a gorgeous granulating gold earth.
• Raw Sienna PBr7 DS. This is a slightly more orange yellow earth, but it mixes quite differently from yellow ochre, making it useful to have both.
• Quinacridone Burnt Orange PO48 DS. This is a lovely colour that creates and incredible range with phthalo blue, but I don't use it much. i keep it as a comparison with burnt sienna and transparent red oxide.

Sixth row

• Transparent Red Oxide PR101 DS. I just love this colour. It's a brighter, more orange and more wildly granulating pigment than burnt sienna. I like to have both in my palette - this for rusty effects, the burnt sienna for a more subdued colour.
• Burnt Sienna PBr7 DS. A basic palette colour, this is a perfect hue to wash down to a skin-tone with lots of water, and to mix with blues for lovely greys. 
• Indian Red PR101 DS. This is the most opaque watercolour, but that doesn't mean it can't be used with lots of water for lovely granulating effects. I love it with yellow ochre (or my mixed granulating gold) and cerulean chromium for a gorgeous earth primary palette.
• Piemontite DS. There is a surprising soft dusty pink in washes, with a deep red-brown in mass-tone - this is perfect for rusty effects, along with transparent red oxide.
• Burnt Umber DS PBr7. It's not an essential colour as it is easily mixed, but in a 20-colour palette I like to have burnt umber as a convenient warm brown.
• Raw Umber PBr7 DS. This is more difficult to mix, and varies considerably from manufacturer to manufacturer. I love this cool deep brown, which is more difficult to mix. It's one of my ultimate mixing set.
• Jane's Grey PB29 + PBr 7. A convenience mix that I make up 60ml at a time. It is granulating and liftable so perfect for skies, shadows and works as a neutral tint to darken other colours. A basic palette colour for me as it saves time when painting.
• Lunar Black PBk11 DS. I don't tend to use black pigments but this is an exception as it is exceptional in its granulation. It creates incredible patterns as the pigment floats and moves - such fun :-)