Some "generic" blends which work well on some flies you can darken or lighten the blend with various furs, depending on what you are trying to achieve;
Donegal olive ( a popular Irish blend used on various flies);
equal parts of , Green, Bright Yellow, Scarlet, Light Blue, Golden Olive, Orange. You can add hare fur to this as well.
Sooty Olive. Dark olive mohair blended with dark brown hare fur ( or other fur).
Irish Claret. Made from mohair or seal fur using blends of scarlet and purple, sometimes black or brown may be added.
Killerbug blend;
Here is a pattern and the mix:
Hook, size 16 to size 6 long shank!
Underbody 1. Lead wire, Overwound with thread, and varnished either with clear varnish to seal the lead before applying silver tinsel, or with the colour as desired, for the particular dressing. Here, Margaret Astor Diamant Red No. 488, which is a dark blood red. This simulates the original underbody of dark red copper wire, and I fancy is somewhat more effective. One may also use orange or other red shades as well.
Underbody2. Silver lurex. Best over the "damp" varnish.
Body. Dubbing made of the following mixture *.
Rib. gold (brass) wire.
*
Add two pinches of teal blue mohair, dyed hare belly fur (or soft seals fur), one pinch of hot orange mohair, hare fur (or soft seal fur), two pinches of white antron, one pinch of clear antron, and one pinch of soft crimson mohair or crimson hare fur (or soft seal fur), to twenty pinches of pre-blended fawn hare body guard and underfur. Blend well so that the colours "disappear" in the general fawn colour.
The exact shade can be adjusted by using darker fur and other blending colours. One can obtain almost the exact shade of the 477 and its varying texture. Indeed, when corretcly mixed and tightly dubbed, one can not tell the difference, either dry or wet.
You can dub sparingly, keeping the fly slim, but still covering the lurex. Or you can dub a bit more heavily, and brush the fly to shape afterwards. The lead underbody must be varnished (nail polish) before winding the lurex and dubbing, as it will otherwise bleed and ruin the fly quite quickly. If you use the red varnish underbody, then leave out the crimson hare fur. The underbody must be completely dry before you dub or wind the body, and especially when using the red varnish underbody.
This rather weird purply brown colour ( the colour of the wool when wet over a copper or red varnished body) is very attractive to grayling, (and trout!), and they will actually pick it up off the bottom. The lurex is necessary to make it "shine" when wet. It will work with a white painted hookshank as well, if you prefer lighter flies, but it is most effective on the bottom. The lurex or white shank underbodies give different effects compared to the red / orange varnish underbody.
Doubtless there are other effective mixes, but this one works well. A version with a pinch each of bright green, bright yellow and dark red/brown dubbing added to ten pinches of hare body fur, over a white hook shank ( denso tape), works very well for trout in summer, and a version with white Antron mixed in the same hare dubbing (White, not transparent) works well as a shrimp pattern in the ocean.
( I will have to find my base list before I can finish this list)
Some blends you will already know, like "Tups" and a couple of others although there is a lot of discussion about it you can blend the "colour" very well using mohair and some furs.
I use a system on my containers like this;
Dubbing system
HB1/PYM1 = Harebody 1 Pale yellow mohair1 etc. This tells me how many pinches of what are in the mix. I aso label sme stuff according to the flies I am going to dress with it.
Hare fur itself has a lot of various colours and many dressers blended fur from various parts of the hare, some only using the mask and ears, to get the colours they wanted.
Just about any fly will work better when the body is blended correctly. For claret, it is better to mix several shades of claret, light, medium and dark, and perhaps some dark and some red hare fur or squirrel fur than use one shade. The blends per se are not particularly critical on some things but the blend itself makes a huge difference. Such flies invariably catch better than those made with single colours.
Some colours like fiery brown can be blended but the dye used on the base mohair ( or fur )is also important.Most modern dubbings give the correct reflected light colour but an incorrect transmitted light colour of auburn/ orangey brown. Some original patterns devised by Rogan of Ballyshannon used fur that had been stained in matured Jackass urine which gave it a warm yellowy glow when seen by transmitted light. A colour reminiscent of the yellow brown of an autumn leaf.
The only way to achieve that effect with modern dyes is to first dye the fur bright golden yellow then overdye it with a mix of gold and fiery brown.
You can use some fur blends to achieve this colour as well.
Very many dressers were well aware of the importance of translucence and transmitted light and took this inot account with their dubbing.
You may also find this of interest;
http://www.flyfishingnetwork.com/FFN/Cu ... 2Jack.html
I have a lot of information on this subject, some collected and a lot of my own, but I don't have access to all of it right now I will have to transfer some notes and data from some old backups before I can get at it. If I have time I will try to do that in the next few days.
Some flies work well at certain times with a specific blend of materials. I only use that blend for that fly. There are some "universal" or "generic" blends for some things as given above, but any given fly will only work best with the blend made for it, and using that blend on another fly is pointless. Many olives work a very great deal better when made with blended materials. The exact blend depends on the flies you want to imitate, and "graduated" body flies work best of all in most cases.