This is an old tutorial of mine, just translated it in English and shortened a little bit. It should take about hour and a half including basings. You should definately use wetpalette, because it makes work so much faster and easier. I painted five of these with these instructions and it took 3,5 hours. Not bad. But back then I was in constant hurry
Base with Citadel Chaos Black Spray.
First layer is mix of Game color Cold Grey and Citadel Ultramarine blue 1/1. I I'd had Citadel Shadow grey I would've used it.
Shoulder pads Yvanden Darksun and reds Mechrite red. Metallics Boltgun metal.
Badab Black wash over all blue and red parts. Avoid yellow unless you're painting Nurgle. After this another layer of Bluegrey
Mix Bluegrey with Game color Wolf Grey about 1/1. Dilute well (I used water). Several thin layers one after another.
Stages.
Golden yellow for yellow parts and mithril silver for boltgun parts.
Highlight red with first Blood Red and then Blood angel orange. Add some white dots to make it look like shiny. And that's a cookie by the way.
Dheneb stone for the face, wolftail on gun and purity seals.
Gryphonne sepia wash on face
Devlan mud wash for knee symbol, shoulder symbol and the beard. Then add some Devlan mud to bring shadows on powerfist, face and all the recesses. Sharp and thin lines with small brush 00, 3/0 or fine detail brush.
Yellow highlights are a mix of Golden yellow and Bleached bone 1/1. More Devlan mud for recesses.
Skull White highlights for yellows and Wolf grey tp armour.
Gun cover(?) Dark angel green, Gun pattern golden yellow/bleached bone mix and highlight the greens with Scorpion green. Another layer of Devlan mud on tail and then drybrushlightly with cold grey and after that with wolf grey.
Gem's painted with Blood red, highlighted with Blood angel orange and that small dot is Skull white. Powerfist runes are scorpion green, which is diluted with water and applied to recesses.
Result.
As I said this is old tutorial, but please ask and comment if you find something useful. What's that Green part all over storm bolter in English?
I have also Speedpaint tutorials for Necron destroyer and Plaguemarine. I'll post them here some day when I get them translated