37. GRE was informed that the Working Party on General Safety Provisions, at its recent session, had adopted amendment proposals on colours to Regulation No. 121 (Identification of controls, tell-tales and indicators) (GRSG-113-42 and GRSG-113-39). GRE supported the short-term solution proposed in GRSG-113-42 and noted that the long-term solution (GRSG-113-39) would be published as an official GRSG document and presented to GRE.
43. Recalling discussions at the previous GRSG session on the handling of colour changes of controls, tell-tales and indicators, the expert from OICA presented ECE/TRANS/WP.29/GRSG/2018/6 as a long-term solution. He explained that the proposal aimed to remove the references in Table 1 to footnote 18 and to only keep the reference to standard ISO 2575:2004. GRSG noted study reservations by the experts from France and the United Kingdom. GRSG agreed to resume consideration of this subject at its next session.
49. The expert from OICA presented ECE/TRANS/WP.29/GRSG/2017/18 to clarify footnote 18 where tell-tales Nos. 1 and 19 were combined. Some experts were of the opinion that footnote 12 already offers that possibility. Following the discussion, the expert from OICA offered an alternative proposal GRSG-113-39 that simplifies the handling of colour changes of tell-tales and to remove footnote 18 and all references to it. The expert from France preferred to keep the existing text of footnote 18 and to only insert under symbol No. 1 a reference to footnote 18, as reflected in GRSG-113-42. GRSG agreed to go forward with a two-step approach and adopted ECE/TRANS/WP.29/GRSG/2017/18 as reproduced below.
| No. | Column 1 | Column 2 | Column 3 | Column 4 | Column 5 |
| Item | Symbol 2 | Function | Illumination | Colour | |
| 1. | Master lighting switch
|  1, 18 | Control | No | |
| Tell-tale 12 | Yes | Green |
50. The secretariat was requested to submit the proposal to WP.29 and AC.1 as draft Supplement 10 to the original series of amendments and Supplement 3 to the 01 series of amendments to UN Regulation No. 121 for consideration at their March 2018 sessions, subject to the endorsement of the Working Party on Lighting and Light Signalling (GRE) at its October 2017 session. (Note by the secretariat: At its seventy-eighth session, GRE endorsed the principles for amending UN Regulation No. 121 as proposed by GRSG.)
51. As a second step, GRSG requested the secretariat to distribute GRSG-113-39 with an official symbol, for consideration at the next GRSG session and to also circulate it all WP.29 Working Parties concerned.
49. The expert from the Republic of Korea recalled the discussion on GRSG-115-14-Rev.1 at the previous session, to add into UN Regulation No. 121 a new symbol for “power on/power off” controls in vehicles equipped with an electric powertrain, such as electric vehicles. He thanked GRSG for the comments received, concluded that the current symbol in the UN Regulation was sufficient and that no further follow-up was necessary.
50. GRSG endorsed the request by OICA to defer discussion on ECE/TRANS/WP.29/GRSG/2018/6 to a further session.
51. GRSG agreed to resume consideration on this item at its next session in October 2019.
51. The expert from OICA recalled the discussion (ECE/TRANS/WP.29/GRSG/2018/6) at the previous GRSG session on the handling of colour changes of controls, tell-tales and indicators by deleting footnote 18 to table 1 and inserting only a reference to standard ISO 2575. Underlining the importance of colour for tell-tales, the expert from France preferred to keep footnote 18. The expert from OICA offered to review the proposal and to insert a new footnote for the tell-tales that impose colour. GRSG agreed to resume consideration of this subject at its next session on the basis of a revised document jointly prepared by the experts from France and OICA.
54. The secretariat briefly introduced GRSG-113-39 to inform GRPE on activities that could be relevant. He invited delegates to consult the document and submit remarks if necessary.