Hi Paris, just to clarify a few points, and then make a few suggestions.
I`ve never used light/fair/blonde colours when I wore Toppers and needed to re-colour my [faded] system-hair to again match the shade of my growing hair, because my own is a dark brown and system colour was `1b`[ off-black/brown] so the colour I was using was very dark. I hope someone who wears fair/blonde hair can give you some help / tips on what`s worked for them. I never used those `basic`items/products that you mention, which are freely-available.... I used Salon-grade compound and peroxide mixed.... the advise not to leave the dark colour on the hair for too long is because they can go too `deep`very quickly and look much darker than the growing hair, and it`s best to avoid that. However, in the case of what you need/want which is to make a fair/blonde colour `lighter`, my guess [and it IS a guess] would be to leave it on longer then you would with a darker mix because you`re trying to `lighten`the colour rather than deepen it, so it will probably take time for that shade to take effect..... again, as with issues guys have when trying to bleach Knots, depending on what way the factory made the hair `blonde`, may affect your efforts...did they use fabric-dye or `normal` colouring compound.... I`m wondering would a `weak`solution of fabric -dye remover help to lighten the colour without using actual colouring solution? Maybe if you try it out on a very small area and see what if any effect it has ? I think lighter colours and shades of blonde can be hard to get matching, as there are so many `in between`shades. If you want to re-try a `normal ` colouring product, go for one like `Wella Koleston` ....it`s important to get the nearest one [as far as you can judge] to what you want, obviously. Have a look at this ----there are 7 cartons ..hover your mouse/cursor over each one......a `list`opens alongside the individual box as you hover...click on one of the colours listed which you think might be suitable--it will appear in the box to the right..... the number in the box is the colour-number which you need to buy or order on line so you get that colour. I find looking at colours on a screen very very tricky to really `` see``....... maybe if you ask a stylist in a women`s hair salon what number would you order so that you get a match for your growing hair....... http://www.wella.com.ph/kolestonshades.html# just hover the cursor over the lists and you`ll get the little picture of it and the shade-number . Have a look at the `Amazon UK ` site [I think there is a French `Amazon`site too ?] as you should be able to order from it http://www.amazon.co.uk/s/ref=nb_sb_ss_c...on+perfect There are several pages with various shades available .....if you`re buying that item, you`ll need Creme Peroxide too...
http://www.amazon.co.uk/s/ref=nb_sb_ss_c...creme+pero I think the 9% one is best. You simply squeeze out a length of paste from the tube into a glass bowl , in a straight line. Pour out an equal `length` of peroxide alongside it in the bowl. Mix the two together until you have a smooth [no lumps] paste and apply that to the hair as soon as it`s mixed...... you`ll have to `experiment` a bit with the timing/s ..... I`m afraid I can`t give you any exact guidance on this because , as I said, I have never used the lighter colours so maybe someone who has can chip in with a few tips.
P.S. I think what Hair Scare suggested would probably be easier..your growing hair would be easier to make a little darker / tone-down [using the Koleston] because in effect the system hair needs `bleaching` as he suggested and which is why I mentioned the possibility of using a [weak] solution of fabric-dye remover ---to help lighten the factory-made colour of the system hair....it would be much more straightforward to `treat`your growing hair.